NTSB Issues 17 Safety Recommendations After Key Bridge Collapse — Mislabelled Wire and Power Failures Cited

The National Transportation Safety Board (NTSB) released 17 safety recommendations after concluding that a mislabelled signal wire and subsequent power failures led the 213-million‑pound container ship Dali to strike the Francis Scott Key Bridge in Baltimore, triggering the bridge's collapse and killing six people.

Key findings

Initial cause: The NTSB determined the first underway blackout was caused by a label placed incorrectly on a signal wire during the vessel’s construction. That label prevented a good connection at a circuit breaker, producing a 58‑second power outage.

Chain of failures: Although the crew found the tripped breaker and restored power within 58 seconds, a fuel feed pump that supplies the ship’s generators required a manual restart. The pump in use was a maintenance‑type unit not intended for operation underway and had no automatic backup. When fuel lines to the generators ran dry, the Dali experienced a second, longer blackout and lost steering, bow thruster, key water pumps and much of the vessel’s lighting and essential equipment.

At the time of the second outage the ship was roughly three ship‑lengths from the bridge. Despite the pilots’ proper responses, the vessel could not be brought under control before it struck a bridge pier.

Recorder and investigation challenges

Investigators also faced difficulties extracting usable data from the vessel’s voyage data recorders (VDRs). Reported problems included missing recordings during the first blackout, the absence of recorded communications between the bridge and engine room, destructive mixing of audio channels, inadequate playback software, and trouble downloading the full onboard data set or converting proprietary files into common formats.

Recommendations and next steps

The NTSB’s 17 recommendations aim to prevent similar disasters and include:

• Using thermal imaging to detect loose wiring across fleets;
• Standardizing wire‑labeling rules and inspection protocols;
• Requiring appropriate onboard pumps and automatic fuel feed safeguards for generators;
• Improving voyage data recorder reliability, accessibility and data formats;
• Implementing warning systems for motorists on bridges in emergencies;
• Requiring vulnerability risk assessments for bridges at risk of ship strikes.

The NTSB has urged vulnerability assessments for 68 other bridges across 19 states that span waterways used by cargo vessels and were built before 1991 without current ship‑strike risk evaluations. Examples named by investigators include the Golden Gate Bridge; several New York City spans (Brooklyn, Manhattan, Williamsburg, George Washington and Verrazzano‑Narrows); Pennsylvania’s Walt Whitman and Benjamin Franklin bridges; Florida’s Sunshine Skyway; and Michigan’s Mackinac Bridge.

“The MDTA maintains that the collapse of the Francis Scott Key Bridge and the tragic loss of life were the sole fault of the DALI and the gross negligence of its owners and operators. The Key Bridge was approved and permitted by the federal government and complied with those permits.”

Synergy Marine and Grace Ocean Investment Limited thanked the NTSB for its “professionalism and technical rigour” and said they cooperated fully with the investigation. Earlier legal filings show Grace Ocean and Synergy agreed to a settlement of nearly $102 million to resolve a civil claim alleging negligent maintenance and cost‑cutting contributed to the collision.

The NTSB will finalize and publish a revised report and formally issue the 17 recommendations in the coming weeks. While the board has no enforcement power, its recommendations are frequently adopted voluntarily; the chair noted a historical closure rate near 83% for implemented safety proposals.

Investigators quoted: NTSB Chair Jennifer Homendy emphasized the need for implementation: “In order to see safety change, we need our recommendations implemented.” Marcel Muse, the NTSB investigator in charge, summarized the technical sequence of outages, and Sean Payne from the recorder division outlined the VDR challenges investigators encountered.

The NTSB’s findings underline how a single mislabelled connection and inadequate redundancy can cascade into catastrophic consequences — and they outline practical steps intended to reduce the risk of a repeat tragedy.