Federal investigators say a hidden flaw in a cargo ship’s electrical system, combined with inadequate protections on the bridge itself, led to the catastrophic collapse of Baltimore’s Francis Scott Key Bridge and the deaths of six workers.
At a public board meeting in Washington, D.C., on Tuesday, Nov. 18, the National Transportation Safety Board (NTSB) outlined its findings on the March 26, 2024 collision between the container ship Dali and the bridge.
According to the NTSB, a “loose wire in the ship’s electrical system caused a breaker to unexpectedly open — beginning a sequence of events that led to two vessel blackouts and a loss of both propulsion and steering.”
Investigators determined that wire-label banding had prevented the wire from being fully inserted into a terminal block spring-clamp gate, creating an inadequate electrical connection. NTSB officials believe the label was improperly placed when the Dali was being built, CNN reported.
Although the crew managed to restore power roughly a minute after the first blackout, a second outage followed. This time, the loss of power stemmed from low fuel pressure: a flushing pump that supplied fuel to the ship’s generators had stopped and needed to be manually restarted, ABC News reported.
The crew was ultimately unable to regain control of the nearly 1,000-foot vessel in time to avoid striking the Francis Scott Key Bridge.
“Investigators found that the pilots and the bridge team attempted to change the vessel’s trajectory, but the loss of propulsion so close to the bridge rendered their actions ineffective,” the NTSB said in its news release.
The agency also pointed to shortcomings on the infrastructure side. It concluded that “contributing to the collapse of the Key Bridge and the loss of life was the lack of countermeasures to reduce the bridge’s vulnerability to collapse due to impact by ocean-going vessels, which have only grown larger since the Key Bridge’s opening in 1977.”
Six construction workers who were repairing the bridge at the time died in the collapse. Another worker survived but suffered serious injuries, and one crew member from the Dali sustained minor injuries.
During Tuesday’s hearing, officials underscored how difficult it was to pinpoint the problem wire among thousands running through the ship — a task one comparison likened to searching for a single loose bolt in the Eiffel Tower, according to NBC affiliate WBAL.
NTSB investigator Todd Gianellon explained that while the crew periodically checked the ship’s wiring system, they had no specific guidelines for inspecting individual wire connections. He also noted that the vessel was not required to use infrared thermal imaging technology, which might have detected the faulty connection earlier, according to the Associated Press.
In her opening remarks, NTSB Chair Jennifer Homendy emphasized that the disaster was avoidable.
“On behalf of the entire agency, I want to extend my deepest sympathies to the families and friends who lost loved ones in this truly heartbreaking tragedy, as well as the survivors who were injured,” she said. “The fact is, we shouldn’t be here today; this tragedy should’ve never occurred … lives should’ve never been lost. As with all accidents we investigate, this was preventable.”
The NTSB’s complete final report on the collapse is expected to be released in the coming weeks.
