Ship that hit US road bridge lost power before fatal collision due to a loose wire

A single loose wire on the container ship that crashed into and partially destroyed a US road bridge, led to the vessel losing of power just before the fatal collision, investigators have concluded.

The US National Transportation Safety Board (NTSB) has found that the unconnected electric cable meant the Dali experienced a loss of propulsion and steering less than a mile from Francis Scott Key Bridge in Baltimore. The collision on 26 March 2024 that followed collapsed a span of the bridge and killed six construction workers who were unable to escape in time.

It led to the blockage of the mouth of one of America's busiest ports for almost three months. Investigators found that an improperly placed label on the wire prevented it from being fully inserted, causing an inadequate connection.

The NTSB's chair said locating the loose wire was like trying to find a single loose rivet on the Eiffel Tower. The board has praised the ship's crew.

"The crew's actions were as timely as they could be, and they were appropriate and also impressive considering the circumstance," board member Michael Graham said. But he called on the maritime shipping industry to strengthen its safety systems and better manage risks to bring it into line with the rigorous approach taken in aviation.

"Many of these issues we have discussed today as part of this accident could have been identified, addressed, and either mitigated or eliminated," Mr Graham said. The far reaching consequences of the accident are continuing.

State officials have more than doubled the projected cost of the bridge rebuild from an upper estimate of $1.9bn (£1.4bn) to $5.2bn (£3.9bn) - with the reopening date pushed back to late 2030. How to prevent future tragedies In March, the board called for urgent safety assessments of 68 bridges in 19 US states including famous crossings like the Golden Gate Bridge in San Francisco and New York's Brooklyn Bridge.

The organisation found that countermeasures to reduce the vulnerability of the bridge from ships could have been implemented if a vulnerability assessment had been conducted by the Maryland Transportation Authority The board has now issued numerous recommendations to try to prevent future catastrophic collisions. Major bridges should consider adopting motorist warning systems that can immediately stop motorists from entering bridges in an emergency.

The Baltimore bridge, like many others, was not equipped with a warning system to prevent vehicles entering. But police managed to clear and halt traffic on the bridge before the collapse, despite only having about 90 seconds to do so.

Read more:Owner of cargo ship agrees to pay $102mFBI opens criminal probe into Baltimore bridge collapse If traffic had not been stopped, it is likely that the death toll would have been much higher. Police officers were discussing how to best evacuate the six workers who were on the bridge moments before the entire structure collapsed.

Other recommendations include the periodic inspections of high-voltage switchboards and proposed changes that would allow ships to recover faster from a loss of power. In a joint statement, Grace Ocean (the Dali's manager) and Synergy Marine Group (the Dali's operator) thanked the NTSB for its investigation and stressed that they had fully cooperated with the board.

It said: "Grace Ocean and Synergy Marine Group continue to extend their deepest sympathy to all those affected by the Francis Scott Key Bridge incident of 26 March 2024. "Since the outset, Grace Ocean and Synergy Marine have fully cooperated with the Board, making personnel, records and technical information available as requested.

"We note the Board's findings, including its observations regarding the vulnerability of the Key Bridge's main support pier, as well as the comments relating to aspects of the vessel's electrical arrangements. These matters will be reviewed in detail with our technical teams, the vessel owner and counsel." The NTSB also called on Hyundai Heavy - the company that built the Dali - to incorporate "proper wire-label banding installation methods".

In response the company said that when it delivered the ship "there was no indication that any wire was loose". It added that if any wire were to come loose "over the course of a decade, through vibrations or otherwise, the owner and operator should have detected that in a routine inspection and through normal maintenance".

Synergy Marine Group has been approached for a response to Hyundai Heavy's comments. The NTSB has not specified that the power outage caused the crash.

A probable cause for the crash will be decided at a later date. The FBI is conducting a criminal probe into the collapse..