NTSB issues prelim report of Francis Scott Key Bridge collapse

The National Transportation Safety Board yesterday released the preliminary report into its investigation of the March 26 collapse of the Francis Scott Key Bridge after it was struck by the container ship Dali.

The report outlined that the vessel experienced two unexpected electrical blackouts in the early morning hours of March 26 before the ship slammed into the bridge, causing it to collapse into a river at the Port of Baltimore. The report indicated that a primary electrical breaker that feeds most of the ship's equipment and lighting unexpectedly tripped, causing the ship to lose electrical power. The main propulsion diesel engine shut down automatically, and the vessel's propellers stopped.

The ship's crew was able to restore its power, and the senior pilot ordered the anchor dropped. Then, the second blackout occurred. A marine radio call was made to warn all waterborne traffic before the Dali hit the bridge, according to the report.

After the Dali's starboard bow struck Pier No. 17 of the Key Bridge, six spans of the bridge  collapsed into the water and across the ship’s bow. A Dali crewmember, who was on the bow at the time of the accident, told investigators that, as he was releasing the brake on the port anchor, he had to escape from the falling bridge before he was able to reapply the brake.

As the bridge deck collapsed onto the bow of the Dali, another of the vessel’s crewmembers sustained a minor injury while escaping the debris.

The road maintenance inspector had been walking the length of the bridge when the ship struck it. He ran north and made it to the nearest surviving span before the rest of the bridge collapsed. The other seven road crewmembers on the bridge at the time of the collision were in their vehicles and fell with the bridge. One worker was able to free himself from his truck and was rescued by a police boat.

The U.S. Coast Guard issued an urgent marine information broadcast, requesting assistance from passing traffic. Multiple agencies searched for survivors throughout March 26. Six victims were later recovered by divers.

The NTSB, which is the lead investigator into the accident, will continue evaluating the design and operation of the ship's power distribution system, including its breakers. Examination of damage to the vessel will continue when the ship is clear of debris and moved to a shoreside facility.

In addition, the NTSB is examining the pier protection improvements that have been made on the following bridge collapses resulting from marine vessel strikes that the NTSB has investigated: the Sunshine Skyway Bridge in Tampa Bay, Florida; Queen Elizabeth Causeway Bridge near South Padre Island, Texas; and the Interstate 40 Bridge near Webbers Falls, Oklahoma.

To read the full preliminary report, click here.