An investigation into the collapse of Baltimore’s Francis Scott Key Bridge is expected to determine the cause of the incident and could provide new details on what led the outbound vessel Dali to collide with the bridge.
Officials on Tuesday said the National Transportation Safety Board was conducting the investigation of Tuesday’s catastrophe. The independent federal agency is responsible for investigating disasters involving marine traffic, highways, airplanes and railways.
A U.S. Coast Guard briefing report obtained by The Baltimore Sun said the Key Bridge collapse was declared a “major marine casualty.” Those types of investigations are handled by the NTSB’s Office of Marine Safety.
An unconfirmed number of people on the bridge during the collapse are still missing, the report said. All of the personnel on the vessel are accounted for, with no reported injuries.
“Initial reports” suggest a harbor pilot and assistant who were on board reported “power issues, multiple alarms on the bridge, and the loss of propulsion prior to the incident,” the Coast Guard report said.
It added that the pilot will undergo “post-accident drug and alcohol testing.”
NTSB investigators were on the scene as of shortly before 11 a.m., the report said, confirming an earlier NTSB statement that a “go team” was activated to investigate.
A media briefing by NTSB Chair Jennifer Homendy was set for 1 p.m.
Under federal regulations, major marine casualties are incidents that lead to the loss of six or more lives, the loss of a vessel weighing 100 tons or more, property damage above $500,000 or a “serious threat” to life, property or the environment.
The NTSB’s Office of Marine Safety is charged with determining the likely cause of each major casualty event and identifying safety recommendations, according to its website. Investigation reports prepared by the agency can include suggestions for state or federal agencies, vessel owners and industry groups, among others.
A 2022 report from the NTSB, for instance, describes collision and contact investigations that include a towing vessel’s 2021 contact with a lock gate in Louisiana, completed roughly a year following the incident.
In it, investigators evaluated the potential that the tow captain experienced “sleep intertia,” the influence of a tidal current, and the effect of the loss of both the lock’s GPS feed and radio communications as the tow approached, which would limit the captain’s speed indication capabilities.
In that case, the probable cause of the contact was the towing vessel captain’s “decision to assume the helm watch and attempt a predawn transit into the lock immediately after awakening.” The “lesson learned,” the agency report said, was that mariners should fully recover from sleep “before taking a watch and performing critical duties.”
More recent reports examine onboard fires, a fishing vessel’s capsizing and sinking and a collision between a tugboat and tanker.