NTSB Identifies Loose Wire as Cause of Dali's Power Failure Leading to Key Bridge Collapse

The National Transportation Safety Board (NTSB) has concluded that a loose wire was the primary cause of the cargo ship Dali's power failure, leading to its collision with Baltimore's Francis Scott Key Bridge on March 26, 2024. The impact resulted in the bridge's collapse and the deaths of six construction workers.

The NTSB's investigation revealed that the Dali experienced multiple power outages before the collision. An improperly installed wire, which had loosened over time, disconnected from its breaker, causing the initial loss of propulsion and steering. This issue was compounded by safety deficiencies in the ship's machinery and electrical systems, hindering full recovery after the blackout.

NTSB Chair Jennifer Homendy emphasized the preventable nature of the incident, stating,

The investigation also highlighted that the Maryland Transportation Authority had not conducted a vulnerability assessment of the Key Bridge, as recommended by the American Association of State Highway and Transportation Officials. Such an assessment could have identified the bridge's susceptibility to collapse from vessel collisions.

In response to the findings, the NTSB issued 17 new safety recommendations aimed at preventing similar incidents in the future. The Maryland Transportation Authority is reviewing these recommendations and has announced plans to rebuild the bridge with enhanced protective measures. The reconstruction is estimated to cost between $4.3 billion and $5.2 billion, with completion expected by late 2030.