Dale Payette of Cashman operates The Pulverizer from Sterling Equipment, with the heavy-lift cranes Weeks 533 and Chesapeake 100 visible in the background.
Photo: US Department of Defense / DVIDS.
The US National Transportation Safety Board (NTSB) said on Tuesday that a weakened electrical wire caused the power failure on the container ship Dali, which crashed into the Francis Scott Key Bridge in Baltimore in March 2024. The impact killed six workers and led to the total collapse of the bridge.
The NTSB is holding hearings in Washington, D.C., to determine the probable cause of the incident, in which six construction workers lost their lives while carrying out maintenance on the bridge.
Board staff said they are recommending that ship operators:
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carry out regular inspections of high-voltage switchboards, and
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implement design and procedural changes that allow vessels to recover more quickly from loss of power.
The NTSB had previously reported that Dali experienced multiple power losses before striking the Key Bridge, including an outage during maintenance in port and another shortly before the casualty.
Power interruptions at sea are not uncommon, and the agency is now considering new safety recommendations aimed at preventing similar catastrophic allisions with critical infrastructure.
Bridge safety review across the United States
In March, the NTSB called for an urgent safety assessment of 68 bridges in 19 states, including landmark crossings such as:
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the Golden Gate Bridge,
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the Chesapeake Bay Bridge,
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the Brooklyn Bridge, and
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the George Washington Bridge.
The review focuses on bridges built before 1991 that are used by oceangoing ships but have not undergone a formal vulnerability assessment.
Concerns were further heightened after a Mexican Navy training ship struck the Brooklyn Bridge in May, raising fresh questions about the risks posed to ageing bridge structures by large vessels.
Power loss timeline and soaring replacement costs
Last year, the NTSB said that Dali lost electrical power roughly four minutes before the collision when electrical breakers unexpectedly tripped. The blackout cut power to all shipboard lighting and most systems while the vessel was about 0.6 miles (1 km) from the bridge.
Initial estimates put the cost of a new bridge at $1.7–$1.9 billion, with construction expected to be completed by late 2028. However, state officials announced on Monday that they now expect the cost to rise to $4.3–$5.2 billion, with traffic not expected to resume over the new crossing until late 2030.
The reasons cited for the increased cost include:
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a new, more robust pier-protection system, and
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a longer and higher bridge design aimed at improving safety and resilience.
Meanwhile, the FBI continues a criminal investigation into the collapse, examining all factors that contributed to the disaster.
