Loose wire fault identified as root cause of Baltimore’s Francis Scott Key Bridge collapse

A detailed investigation has confirmed that a loose electrical wire aboard the container vessel involved in the 2024 Francis Scott Key Bridge disaster initiated the sequence of failures that led to the collapse. The National Transportation Safety Board (NTSB) determined that the wire triggered an electrical blackout which removed propulsion and steering control as the ship approached the bridge. The event resulted in six fatalities and widespread structural loss, significantly impacting regional mobility and port operations.

The faulty wire had not been fully seated within a terminal block, creating an inadequate connection that caused a breaker to open unexpectedly. The vessel experienced two blackouts within moments, leaving the navigation team without the ability to change course. With the ship drifting toward a key support pier, the impact forces exceeded the bridge’s structural resilience, which had not been enhanced to meet the demands of increasingly large modern vessels.

Authorities noted that similar earlier incidents involving smaller ships had caused only minor damage. The dramatic increase in vessel size since the bridge’s construction contributed to the severity of the event and highlighted critical gaps in bridge impact protection for major water crossings.

The collapse prompted an extensive review of bridge vulnerability nationwide. Agencies have since been urged to assess vessel-collision risks and adopt protective measures where required. Repair and reconstruction efforts are ongoing, with revised cost estimates reaching approximately five billion dollars. Updated design considerations now incorporate lessons learned from the investigation, focusing on resilience, navigational hazard assessment, and infrastructure adaptation to evolving maritime conditions.

Following, a video discussing the NTSB findings.