Baltimore, Maryland - The head of the US National Transportation Safety Board (NTSB) on Thursday accused Maryland authorities of negligence ahead of last year's collapse of the Francis Scott Key Bridge, near the Port of Baltimore.

NTSB chairwoman Jennifer Homendy told a press briefing that the Maryland Transportation Authority (MDTA) should have "conducted a vulnerability assessment" of the bridge in case a ship collided with it.

On March 26, 2024, the Singapore-flagged M/V Dali lost power and plowed into a support column of the Francis Scott Key Bridge, causing it to collapse and killing six road workers who had been filling potholes overnight.

If the assessment had been completed "the MDTA would have been aware that this critical, essential bridge was above the AASHTO threshold of risk for catastrophic collapse from a vessel collision," Homendy said, referring to a guide by the American Association of State Highway and Transportation Officials (AASHTO).

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An NTSB investigation determined the assessment would have found the bridge "was almost 30 times greater than the risk threshold" for bridges deemed critical and essential.

Homendy also warned that many other bridges across the US were at risk of a similar catastrophe.

"The 30 owners of 68 bridges over navigable waterways frequented by oceangoing vessels are likely unaware of their bridges' risk of catastrophic collapse from a vessel collision," she said.

Homendy urged the bridges' owners to reassess "the potential need to implement countermeasures to reduce the bridges' vulnerability."

The list of bridges at risk includes the nearby Chesapeake Bay Bridge outside Baltimore.

Preparations for rebuilding the Key Bridge – an estimated $2 billion endeavor – are already underway, according to the MDTA, with the new bridge expected to reopen to traffic by 2028.