The container ship Dali is shown amidst the wreckage of the collapsed Francis Scott Key Bridge in Baltimore, Tuesday, March 26, 2024. Six people are missing after the Dali lost power and crashed into one of the bridge's support columns.

Federal officials investigating the 2024 collapse of the Francis Scott Key Bridge in Baltimore said the deadly incident was "preventable" at a board meeting on Nov. 18.

The Dali - a 984-foot container ship - lost power, propulsion and steering and struck a pier that supported the central span of the bridge on March 26, 2024. The bridge then fell into the Patapsco River, killing six construction workers.

The National Transportation Safety Board said a loose wire led to the power failure during a hearing in Washington, D.C., to address the probable cause of the incident and recommendations to prevent something similar from happening again.

"The fact is, we shouldn’t be here today; this tragedy should’ve never occurred … lives should’ve never been lost," Jennifer Homendy, chairwoman of the National Transportation Safety Board said in her opening remarks. "As with all accidents we investigate, this was preventable."

The board staff said they are recommending operators complete periodic inspections of high voltage switchboards and proposing changes that would allow ships to more quickly recover from loss of power.

The findings and recommendations come after state transportation officials announced the replacement bridge will cost between $4.3 billion to $5.2 billion and won't open until late 2030, an increase in cost and delay in time from earlier estimates. They cited increased material costs and a new pier protection system as reasons for the increased cost.

What went wrong during the Baltimore bridge collapse?

In the early hours of March 26, 2024, the Dali experienced a low-voltage power outage and lost most of its lighting and essential equipment while seven highway workers and one inspector were on the bridge performing repairs, NTSB investigators said. The NTSB said that the initial low voltage blackout was caused by a loose signal wire that disconnected because its label was placed incorrectly.

Though the crew was required to periodically inspect the ship's switchboard, investigators said the instructions don't provide practical guidance for checking the thousands of wires and doing so by hand would be difficult and extremely labor intensive. The NTSB instead recommended using infrared thermal imaging to check for flaws that may not be visible to the human eye.

Though the pilots and bridge team responded to the emergency in a timely manner, "the vessel's loss of propulsion close the Key Bridge rendered their actions ineffective," NTSB marine accident investigator Bridget Quinn said.

Protocol required the pilots to contact the Coast Guard first, but the senior pilot instead called his dispatchers who then alerted The Maryland Transportation Authority (MDTA) and the Coast Guard. The quick action "prevented a greater loss of life from the bridge collapse," Quinn said.

A little more than a minute before impact, the MDTA duty officer radioed the police officers performing traffic control to stop more vehicles from coming onto the bridge, investigators said. However, the police officers did not contact the inspector on the bridge to warn him of the Dali's emergency, despite previously exchanging cellphone numbers. Instead, an officer planned to drive to the worker's location and alert them once he was relieved by another officer.

Had the "inspector and highway workers been notified of the Dali's emergency situation about the same time the MDTA police officers at each end of the bridge were told to block traffic, the highway workers may have had sufficient time to drive to a portion of the bridge that did not collapse," NTSB highway factors engineer Scott Parent said.

Officials should have known bridge was vulnerable

Parent also said that if local officials had assessed the bridge, they would have found that risk of collapse due to collision was 30 times above the accepted federal threshold, according to findings initially released in March.

Had they done so, officials "would have had information to practically identify strategies to reduce the risk of a collapse and loss of lives associated with a vessel collision with bridge," he said.

Parent said the NTSB identified 68 bridges in 19 states – which reportedly include iconic structures like the Golden Gate Bridge, Chesapeake Bay Bridge, Brooklyn Bridge and George Washington Bridge – have "an unknown level of risk of collapse."

This story has been updated to add new information.

Contributing: Reuters; Michael Loria, USA TODAY

This article originally appeared on USA TODAY: Baltimore bridge collapse that killed 6 was 'preventable,' federal investigators say

Reporting by N'dea Yancey-Bragg, USA TODAY / USA TODAY

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