The latest reports from South Korea now suggest that of the 476 people on board the Sewol, 174 were rescued, 159 bodies have been recovered and 143 people are still missing.

BLAME GAME:

It is human nature to want to blame someone after a tragedy.  But when a disaster of this magnitude occurs, it is time for a nation as a whole to reflect on its safety culture, and not simply blame a few individuals. We should be looking at the safety culture on board the Sewol, in the company that owns and runs the vessel, within the South Korean maritime industry and within South Korean culture as a whole.  It is far too easy to point a finger at a few people, as the South Korean President has done.  To address the real problem and ensure that this type of disaster never happens again, we must identify and address the root cause(s) of the problem and this is likely to be the result of a number of factors, beyond the immediate actions of the Captain and crew.

PREVIOUS DISASTERS:

To put this disaster into context it is useful to compare it to two other Ro-Ro ferries that have capsized in recent history resulting in large loss of life. In 1987 the Herald of Free Enterprise rolled over shortly after leaving port due to her bow doors being opened in less than 4 minutes and claimed the lives of 94 people while in 1994 the Estonia capsized in rough seas within about 15 minutes and claimed the lives of some 850 people.  So Ro-Ro vessels such as the Herald of Free Enterprise, Estonia and Sewol can capsize very rapidly if water gets onto the large open car decks.

HOW MUCH TIME WAS AVAILABLE?:

We believe that the crew of the Sewol first called the coast guard (CG) at 08:56 to say that they were in distress – however, it is not clear how long they waited after realising that they were in trouble before called the CG. It was reported today that the first call to the authorities was actually made by one of the children on board as he was frightened that the ship would sink.  This is believed to be some 3 minutes before the crew made their first call.

From the official transcripts: 

9:10 a.m.

Sewol: Jindo VTS, this is Sewol

Jindo Coastal VTS: This is Jindo Coastal VTS.

Sewol: We’re tilted, so it looks like we’ll flip over soon.

Jindo Coastal VTS: Okay. How are the people on board? Boat A is nearing your boat as fast as possible.

Sewol: We’re so tilted that (we) can hardly move.

9:17 a.m.

Jindo Coastal VTS: Sewol, do you read Jindo Coastal VTS? (four times). How flooded are you?

Sewol: With the boat now tilted at least 50 degrees to the left, people can’t move to their left or right. The crew have been told to wait with their life jackets on. But it’s impossible to check whether they’re actually wearing them. Crew members gathered on the bridge are unable to move. Please hurry up.

So at 09:10 (some 14 minutes after first official message to the CG) they state that the vessel was severely leaning over, but no firm indication as to the degree of heel apart from saying they can hardly move. At 09:17 they estimate that they are on a heel of about 50 degrees, this is some 21 minutes after the crew first contacted the CG and some 24 minutes after the child made his call.

So the vessel appears to have a severe list some 14 to 21 minutes after the crew first radioed the CG to inform them of their emergency. We do not know how long it took them to radio the CG after the incident began, but it appears to be some 3 minutes after the child on board made his call. So it appears that they may have had around 17 minutes (or more) before conditions on the vessel became very difficult.

It will be important to establish when the crew first attempted to contact the passengers and when the message to “stay where you are” was made.

Given that around 17 minutes may have been available before conditions deteriorated to the point that movement became almost impossible, it is unlikely that all 476 souls on board the Sewol would have been able to reach the assembly points from which they could relatively easily abandon the vessel.  Nevertheless, had a command to commence the assembly phase been given at the earliest possible time, it is likely that considerably more of those on board could have been able to reach the assembly stations and therefore been in a position to abandon the vessel.

SAFETY CULTURE:

Given that there appears to have been sufficient time to allow a greater number of people to evacuate from the Sewol, it is important to establish the following: what were the evacuation procedures? How well did the crew know and understand them? What prevented the crew from implementing them?

These questions allude to the safety culture on the Sewol, in the management company, and in wider South Korean society, particularly:

• What were the evacuation procedures on the Sewol?
  • How appropriate were these procedures for a Ro-Ro ferry?
• Are passengers routinely informed of the evacuation procedures prior to departure?
  • How are they informed?
• How familiar were the Captain and crew with their own evacuation procedures?
  • How often did the Captain and crew drill their evacuation procedures?
  • What did the evacuation drill consist of?
  • What was considered acceptable performance in evacuation drills and does this demonstrate an appropriate level of competence and understanding?
• What oversight of the evacuation procedures did the parent company of the Sewol have?
• What oversight of the evacuation training did the parent company of the Sewol have?
• Did the corporate culture encourage or discourage adherence to safety and evacuation procedures?
• What oversight of the evacuation procedures did the Korean maritime authorities have?
• What oversight of the evacuation training did the Korean maritime authorities have?

Similar questions could be asked relating to other operational issues such as those relating to the safe navigation of the vessel, loading and securing cargo and rescue operations.

• Comments on the Costa Concordia Grounding 13 January 2012. Part 1 The Ship Evacuation Process.  http://fseg.gre.ac.uk/blog/?p=110
• Comments on the Costa Concordia Grounding 13 January 2012. Part 2 What do we currently know about the Costa Concordia Incident. http://fseg.gre.ac.uk/blog/?p=117
• Comments on the Costa Concordia Grounding 13 January 2012. Part 3 Repercussions for Passenger Ship Safety. http://fseg.gre.ac.uk/blog/?p=126

In my previous blog I reported what we currently know about the Sewol disaster, based on current media accounts.  Here I will explore to explore the ship evacuation process, what hampered the evacuation of the passengers on the Sewol and some of the implications for passenger ship safety.

The latest reports from South Korea now suggest that of the 476 people on board the Sewol, 174 were rescued, 54 bodies have been recovered and 248 people are still missing.

The sinking of the Sewol bears a striking resemblance to the Costa Concordia incident.  Many factors strongly influential to evacuation outcomes were common to both cases.  Some of these should have assisted the passengers, while others undoubtedly impeded their safe evacuation. The common factors that should have contributed to a favourable evacuation include:

1)    The incidents occurred under the jurisdiction of modern well-developed countries

This should have helped, but it does not mean that the shipping companies involved have a well-developed safety culture, or the regulatory and inspection facilities in each country are well developed and appropriate.

2)    The vessels were relatively modern

The Costa Concordia was launched in 2005, and the Sewol in 1994.  As both are relatively modern vessels they would have benefited from modern design practices and knowledge of safety issues. However, the Sewol was completed in the year of the Estonia disaster.  This disaster lead to a number of significant changes to IMO regulations for Ro-Ro ferries such as the Sewol, but they came too late to impact the design of the Sewol.

3)    The weather was calm

Bad weather can complicate the evacuation process, making it difficult to safely evacuate a large passenger vessel; however, in both cases, the sea was calm, and the conditions were not harsh.  While the water temperature in the case of the Sewol incident was cool, it is unlikely that the passengers would have remained in the water for a dangerously long period of time, especially given (4), (5) and (6).

4)    The vessels were on well-known routes and in busy shipping lanes

If the ship is in unfamiliar waters with little traffic it may complicate the decision to evacuate the vessel as the survivors may have to spend a long time in the water in lifeboats.  However, this was not the case in either of these incidents.

5)    The vessels were close to land

The fact the vessels were close to land meant that help was not far away.

6)    The vessels were in radio contact with the coast guard at the time of the incident

The fact that the vessels were in contact with the coast guard from the start of the incident meant that help was be quick in arriving.

7)    The vessels were not overcrowded and there were sufficient lifeboats for the population

In the case of the Sewol, the vessel was carrying significantly less than the maximum capacity of the vessel. In both cases, there was ample capacity in the available life boats.

8)    The captains were experienced master mariners

Both captains had considerable experience and should have been expert in the handling of their vessels, and the dangers associated with taking on water, particularly, in the case of the Sewol, of taking on water on the car deck.  Both should also have had a good working knowledge of the evacuation process and the need for speed.

Items (1) to (8) meant that the in both cases, these disasters occurred under somewhat ideal conditions and so we should have expected a much better outcome.  Indeed, both cases should have been more survivable, had the evacuation been managed in a more efficient and timely manner. 

In both cases the factors that contributed to the disastrous outcome of these evacuations include: 

9)    The passengers were not required to complete an assembly drill to familiarise themselves with the evacuation process prior to departure

In the case of the Costa Concordia an evacuation drill was not required prior to departure, but within 24 hours of departure.  In the case of the Sewol, as the journey was less than 24 hours an evacuation drill was not required at all.  This meant that it was unlikely that the passengers were familiar with the evacuation procedures.

10) Both Captains failed to start the assembly process within a reasonable period of time

This meant that the passengers were not in a position from where they could rapidly and easily abandon the vessel or be easily rescued by emergency responders, should this prove to be necessary.

11) Counter intuitive instructions were given to the passengers

Not only were passengers not given the command to assemble, they were effectively given instructions NOT TO assemble.  In the case of the Sewol, it is reported that the passengers were instructed to stay where they were, while in the case of the Costa Concordia, passengers were told that there was not a serious problem and that they should go to their cabins.

12) Both vessels capsized but this took more than 30 minutes

In both cases, there would have been sufficient time for most, if not all of the passengers to get to their assembly stations from where they could abandon the ship, had the assembly process started sufficiently early.

13) Failure to launch sufficient lifeboats (or liferafts)

Delay in starting the evacuation process meant that it was impossible to launch sufficient lifeboats in the case of the Costa Concordia, or virtually any liferafts in the case of the Sewol.  Davet launched lifeboats cannot be launched when the angle of heel exceeds 20^O and the liferafts cannot be launched if the crew cannot reach them due to adverse angles of heel.

14) Both captains abandoned the vessel before their passengers and crew had safely evacuated.

In both cases it is reported that the Captain did not remain on board to manage the evacuation of the people in their care.  Essentially they left the passengers to fend for themselves.

Failure to start the assembly process as soon as possible contributed to the disastrous outcome in both cases.

• Why is it so important to start the assembly stage as early as possible?

In an evacuation situation, every second counts and seconds can mean the difference between life and death.  On board a large passenger ship, the evacuation process is usually undertaken in two parts: the assembly phase, and the abandonment phase.  This is explained in more detail in an earlier blog concerning the Costa Concordia (http://fseg.gre.ac.uk/blog/?p=110).

During the assembly phase, passengers are instructed to go to their assembly stations. Passengers will be given lifejackets at the assembly stations, or they will bring their lifejackets from their cabins.  Assembly stations are close to the points from which passengers can embark onto the lifeboats if the captain decides to go to the second phase of the evacuation, the abandon ship phase.  It is vitally important that the assembly phase is completed as quickly as possible because conditions on board may make it impossible for passengers to get to a place from where they can abandon the vessel, if conditions deteriorate, such as if there is a fire on board, or if the vessel is heeling over, as in the case of the Costa Concordia and the Sewol.  If passengers are in the assembly stations it will also be easier for emergency teams to rescue the passengers compared to if they are located deep within the vessel.

Imagine you are in your cabin and you need to get to the assembly station.  Let’s assume that the assembly station is on your deck so you don’t have to climb or descend any stairs.  You will have to get out of your cabin, pass along a corridor running along the length of the vessel and then eventually pass through a corridor running across the vessel linking the left with the right part of the vessel.

When the vessel is upright, this is a relatively easy thing to do and you can pass from left to right or from right to left easily, depending on which side you need to move to (see Figure 1).  If the vessel takes on a slight heel, say less than 5^O, movement is still relatively easy, assuming that you are not elderly or disabled (see Figure 2); however at 20^O of heel, it starts to become very difficult to move up the slope and to control your movement going  down the slope (see Figure 3).  Your travel speed up and down the slope is greatly reduced, resulting in it taking considerably longer to assemble the passengers.  If you have elderly or disabled passengers, it is unlikely that they will be able to move unaided.

Angles of heel from 0 degrees to 20 degrees

When the angle of heel reaches 45^O, it is extremely difficult to move up the slope without travelling at a crawling pace, and you will need to hold onto things such as handrails to progress (see Figure 4).  Going down the slope in a controlled manner also becomes very difficult. If you are elderly or disabled, it is unlikely that you will be able to move, even with assistance. 

At 60^O of heel, it is unlikely anyone will be able to move up the slope, and the only way is down or staying where you are (see Figure 5).  If the passengers have not reached the assembly stations by the time the angle of heel has reached 60^O, it is unlikely that they are going to be able to move across the vessel against the slope. 

Angles of heel from 45 degrees to 60 degrees

If passengers are still in their cabins when the heel is much greater than 20^O, it is unlikely that they will be able to get out of their cabins, let alone make it to their assembly station.  Imagine now that if you had to ascend or descend stairs to reach your assembly station, how much more difficult it would be, compared with simply walking along a corridor!  Even walking along the long corridors running the length of the vessel becomes difficult when the ship takes on an angle of heel greater than 20^O.  The passenger is pulled down to the low side of the corridor and has to walk partially on the floor and partially on the bottom of the wall.  Here again the speed at which the passenger can move is greatly reduced AND the effective width of the corridor is greatly reduced, making it more difficult for crowds to move along the corridor.

This is why it is essential that passengers must complete the assembly process and locate themselves in a place from which they can abandon the vessel easily or be easily rescued if necessary.  So it is essential that the assembly phase of the evacuation is started as soon as possible.  Assembling the passengers does not necessarily mean that they will have to abandon the vessel, but if they need to do so, they will at least be able to.  I find it hard to understand why a captain of a vessel that is in distress – so much so that they have alerted the coast guard – would not have started the assembly process, if for no other reason than as a precaution. In my earlier blog concerning the Costa Concordia (http://fseg.gre.ac.uk/blog/?p=126) I offer some suggestions as why this may happen.  But it may also simply be down to denial.  The captain and senior officers may simply be denying the seriousness of the situation, believing that they can remedy it, and there is no need to evacuate.  If so, this becomes a training issue and one concerned with safety culture, both on board the vessel and also in the operating company that runs the vessel.

• Did social culture play a role in the outcome of the Sewol disaster?

It has been suggested that social culture of the South Korean people had a role to play in the outcome of the Sewol evacuation.  In particular, the suggestion is that South Korean culture demands that people are respectful of authority and are compliant with the wishes of those in authority.  Had the passengers been from a different cultural group they may have reacted differently to the order to stay where they were.

Recent work by my research team as part of an EU FP7-funded project BeSeCu [1,2,3] suggests that social culture may influence the way in which people respond to alarms.  It was noted in this research that when faced with virtually identical situations, groups of people from one culture tended to react significantly more rapidly than groups from other cultures when faced with a fire alarm.  This is further discussed in a paper we published recently with the Royal Institution of Naval Architects, concerning evacuation from large passenger ships [4], as part of the EU FP7 SAFEGUARD project [5].  

However, I am not convinced that simply responding to an instruction from an authority figure is a cultural trait unique to the South Korean people.  Our research into the World Trade Center evacuation [6] suggested that when people in the South Tower of the WTC heard the instructions over the PA system that they should return to their offices, as they were safe in the South Tower, (as only the North Tower had been hit at this time), many did so – and died [7]. Also, many passengers on the Costa Concordia also complied with the instructions of the crew, at least initially. 

Perhaps it is more relevant that the majority of people on board the Sewol were children and so more likely to follow the commands of an authority figure.  This is probably likely to be the case in most cultures.  Furthermore, as with the Costa Concordia disaster, safety culture (or the lack of a healthy safety culture), as opposed to social culture, may have played a more important role in this disaster.

• Assembly drill requirements

As has already been stated, according to IMO regulations, it is not compulsory to have an assembly drill prior to the departure of the vessel for voyages of less than 24 hours; however, as the Sewol and Costa Concordia incidents have tragically demonstrated, fatal accidents requiring the abandonment of the vessel can occur at any point of a voyage, even as little as a few hours after departure. In both cases, the passengers would have benefited from having experienced the assembly process prior to the fatal accident.

The point of the assembly drill is twofold: firstly, and most importantly, to familiarise passengers with the assembly procedures and the location of the assembly stations; secondly, to provide the crew with training in the management of large crowds of passengers.  The need to undertake the assembly drill becomes more critical the larger the number of passengers on board, and the more complex the layout of the vessel.  Indeed, the duration of the voyage is somewhat irrelevant when setting a lower limit for the need to undertake an assembly drill. 

The difficulty for a regulatory body is in defining critical limits on duration of voyage, population size and complexity of vessel layout that are meaningful and not arbitrary; nevertheless, in addition to the current voyage duration criterion, sensible limits could be placed on the other factors.  Addressing complexity, if a significant number of the passenger population is accommodated within cabins, the layout of the vessel will be more complex than a vessel not having cabins.  Thus if a significant number of passengers are accommodated within cabins, the complexity criteria will require an assembly drill.  In terms of the size of the passenger population, if the predicted assembly time for the vessel is within 20% of the maximum allowed assembly time, then the population criteria will be met to require an assembly drill.

So rather than having a single factor (duration of voyage) determining whether or not an assembly drill is required prior to departure, three factors addressing different challenging evacuation issues should be considered:

• Duration of voyage: if the voyage is greater than 24 hours, an assembly drill must be undertaken.  This ensures that the current criterion is maintained.  The longer the voyage the greater the chance that an accident may occur and, hence, that an assembly may be required.
• Complexity of vessel: if more than 30% of the passengers on the voyage are to be accommodated within cabins, then an assembly drill must be undertaken.  This ensures that passengers travelling on vessels with complex layouts will undergo an assembly drill prior to departure.
• Number of passengers: if the predicted assembly time for the vessel is within 20% of the maximum allowed assembly time, an assembly drill must be undertaken.  This ensures that vessels with large numbers of passengers for their size will have an assembly drill prior to departure.

REFERENCES:

1: http://fseg.gre.ac.uk/fire/besecu.html

2: “Behaviour – Security – Culture. Human behaviour in emergencies and disasters: A cross-cultural Investigation.”, Silke Schmidt and Ed Galea (Eds), 2013, Pabst Science Publishers. ISBN: 978-3-89967-867-3

3: Galea, E.R., Sharp, G., Sauter, M., Deere, S.J., Filippidis, L., “Investigating the impact of culture on evacuation behaviour – A Polish Data-Set”, Proceedings of the 5th International Symposium, Human Behaviour in Fire, Cambridge UK, 2012, Interscience Communications Ltd, ISBN 978-0-9556548-8-6, pp 62-73, 2012.

4: Brown, R., Galea, E.R., Deere, S., Filippidis, L., “Passenger Response Time Data-Sets for Large Passenger Ferries and Cruise Ships Derived from Sea Trials”, Trans RINA, Vol 155, A2, International Journal of Maritime Engineering, April-June 2013, pp A97-A103.

5. http://fseg.gre.ac.uk/fire/safeguard.html

6: http://fseg2.gre.ac.uk/HEED/

7: Galea, E.R., Hulse, L., Day, R. Siddiqui, A., and Sharp. G. “The UK WTC 9/11 evacuation study: An overview of findings derived from first-hand interview data and computer modelling”, Fire and Materials, Vol 36, pp501-521, 2012, DOI: 10.1002/fam.1070

• Comments on the Costa Concordia Grounding 13 January 2012. Part 1 The Ship Evacuation Process.  http://fseg.gre.ac.uk/blog/?p=110
• Comments on the Costa Concordia Grounding 13 January 2012. Part 2 What do we currently know about the Costa Concordia Incident. http://fseg.gre.ac.uk/blog/?p=117
• Comments on the Costa Concordia Grounding 13 January 2012. Part 3 Repercussions for Passenger Ship Safety. http://fseg.gre.ac.uk/blog/?p=126

Here I would like to attempt to put together a picture of what we currently know about the Sewol disaster based on current media accounts and make some tentative comments about the possible cause of the incident.  In later blogs we will explore the implications of this incident on passenger safety.

As is the case after every disaster, the world’s media has been flooded with accounts concerning the sinking of the Sewol.   There is so much information flying about it is difficult to keep track of the salient points of the incident.  Here is what I hope a summary of some of the reported key points:

The vessel:

• The Sewol was built by Hayashikane Shipbuilding & Engineering in Nagasaki, Japan in 1994.
• The Sewol is a Ro-Ro ferry.  She has passenger accommodation on the upper decks and a car deck lower down on the vessel.  The vessel has a vehicle ramp in the aft of the vessel.  The vessel can also carry shipping containers.
• Vessel was bought by South Korea in October 2012.
• It is owned by Chonghaejin Marine and the vessel is registered with the Korean Register of Shipping
• The Sewoll was modified from Oct 2012 to Feb 2013.  It is reported that additional accommodation space was added to the third, fourth and fifth decks to accommodate 181 additional passengers (some reports say 117 passengers and some reports also say additional cargo capacity) and that the existing cabin spaces were also modified.  It is reported that the modifications added 239 tons of weight to the vessel (some reports suggest 169 tonnes).
• The Sewol is reported to have passed all required certification and safety checks following modification.
• At the time of her last sailing, the Sewol was 146m long, 22m wide with a gross tonnage of 7000 tons. It could accommodate 921 passengers, 35 crew and space for 220 vehicles.  It could also carry 152 20 foot shipping containers. It had a reported maximum speed of 21 knots.
• The vessel is reported to have 46 lifeboats, but this probably means 46 liferafts.  From the available photographs it is not clear if there are any davet lunched lifeboats.
• On its final voyage it is reported that it was carrying more than 100 cars and lorries, along with a sizable shipment of cargo containers strapped onto the deck.
• Detailed plans of the vessel, showing the layout of the interior and the location of the assembly errors are not available.

From BBC News website http://www.bbc.co.uk/news/world-asia-27087243

The occupants:

• Reports of the total number of people on board during her final sailing varies from 359 up to 476.
• The lower estimate is made up of: 30 crew, 325 students, 15 teachers and 89 other passengers.  However, at the time of writing it is not known precisely how many people were on board.
• Most accounts agree on the number of students at 325.
• Students are from Danwon High School in Ansan, a suburb of Seoul

The voyage:

• She was on a routine voyage which she usually undertakes two or three times per week.
• The route runs from Incheon to the tourist island of Jeju.
• The voyage is reported to last 13.5 hours (some reports say 14 hours).
• On its last voyage, the Sewol sets sail from Incheon on Tuesday 15 April at night.
• The conditions are reported as calm with a water temperature of about 12^OC at the time of the incident.
• It is expected that the passengers do not undertake an assembly drill prior to departure as the voyage is under 24 hours in duration.  Thus by IMO regulations the shipping company is not required to hold an assembly drill.

The incident:

• It is alleged that the Captain (68 year old Lee Joon-Seok) was not on the bridge at the time of the incident.  This in itself is not an issue as the Captain cannot be expected to be on the bridge at all times.  However, the question is whether or not this was a time requiring the Captain to be pilot the vessel.
• It is alleged that the third mate, a 26 year old woman with one year’s experience at the helm of a vessel and five months experience on the Sewol is at the helm.  It is alleged that this was the first time she had the helm of the Sewol.
• It is alleged that the vessel made a sharp turn between 08:48 and 08:49. It is not clear why the sharp turn was made.
• Passengers report hearing a bang and feeling a sever jolt.
• A distress call is made from the Sewol at 08:56 (23:56 GMT) on Wednesday 16 April, vessel begins to heel over.
• At around 09:30 the Sewol is at 60⁰ heel and helicopters begin arriving.
• At around 09:45 helicopters begin rescue operations.
• At around 10:00 vessel is at 90^O heel rescue operations continue.
• At around 10:23 vessel is completely overturned.
• During this period passengers report that they were instructed to remain where they were.
• At the time of writing it is alleged that 46 people are confirmed dead, 174 rescued and 256 are missing.
• Of the suggested 29 crew members on board, 20 including the Captain survived.  It is alleged that the Captain was amongst the first to board rescue boats.  Note that this does not mean that he was amongst the first rescued as helicopters allegedly rescued the first people.

From the Straits Times Web site: http://www.straitstimes.com/news/asia/east-asia/story/south-korea-ferry-disaster-fury-and-questions-grip

Speculation:

There are at least three possible causes for the incident:

1)    The vessel hits an obstruction on the sea bed ripping open a hole in the vessel which suddenly takes on water causing the severe heel.  The bang heard by the passengers was the sound of the vessel hitting the obstruction.

• As this is a regular voyage on a regular route it is unlikely that the vessel would hit an obstruction on the sea bed unless the vessel was off course at the time of the incident.
• The rescue divers may be able to eliminate option 1 if they are able to examine the hull of the submerged vessel.

2)    The sudden turn made by the vessel is beyond the normal operational parameters of the vessel for the loading conditions causing the cargo to become dislodged

3)    The sudden turn made by the vessel causes the vessel to lean into the turn destabilising the cargo and vehicles on the car deck which in turn accentuates the heel.  The bang heard by the passengers is the shifting cargo on the vessel.

• This may be an issue if the modifications to the vessel made the vessel less stable at normal operating situations by raising the centre of gravity of the vessel.
• Alternatively, the cargo may have been incorrectly secured to the deck so that a sudden turn could have dislodged the cargo.