A single loose wire led to the deaths of six workers, the grounding of the container ship Dali and the destruction of the Francis Scott Key Bridge in Baltimore, a safety investigation has found.
Investigators from the US National Transportation Safety Board discovered that the loose wire in the ship’s electrical system caused a breaker to open. A breaker is a safety switch that interrupts the flow of electricity.
Electrical wires can have labels attached to them in a band around the wire (known as “wire-label” banding). In the case of the Dali, an incorrect installation of wire-label banding prevented the correct insertion of the wire into the mechanism and caused an inadequate connection. This led to the electrical blackout, the subsequent loss of propulsion and steering, then contact with the bridge.
The official report also noted that the bridge itself was vulnerable to collapse due to ship strike. That vulnerability could have been addressed by the local transportation authority, as recommended by the American Association of State Highway and Transportation Officials.
The NTSB also found that the quick action of the Dali pilots, the shoreside dispatchers, and the Maryland Transportation Authority prevented a greater loss of life.
