Two blackouts triggered by the unexpected tripping of electrical breakers caused a container ship to slam into Baltimore's Francis Scott Key Bridge in March, sending it tumbling into Baltimore Harbor and killing six people, federal investigators said in a preliminary report released Tuesday.
The National Transportation Safety Board report said the 947-foot Singapore-flagged Dali suffered a pair of power losses in the minutes before it struck the bridge, leaving the ship without propulsion to help steer away from one of the bridge's piers. After radioing for help, the crew dropped its anchor in a last-ditch attempt to avoid a collision.
But it was too late: A crew member told investigators that as he was releasing a brake on the anchor, he had to escape the collapsing bridge.
The NTSB is still investigating factors that might have played roles in the crash, including the design and operation of the Dali's power distribution system, which includes the breakers, the report said.
The report noted, however, that tests of the Dali's fuel did not identify any quality concerns. The NTSB is also helping local authorities decide whether the protection of bridge piers in the harbor need to be improved, the report said.
The Dali, which had been chartered by the Danish shipping giant Maersk, was bound for Sri Lanka when it struck the bridge at 1:28 a.m. March 26. Minutes before the crash, the ship's lights went out, then briefly flickered back on, and black smoke billowed from the stack — signs of the power losses.
Seconds after impact, the bridge, considered a jewel of the city, collapsed into the depths of the Patapsco River, killing six roadwork crew members who were on it in what may be the most expensive maritime disaster in history. Two workers were rescued from the river. All 22 crew members on the ship survived, along with two pilots who were helping the Dali navigate the harbor.
The catastrophe took seconds, as captured by video that showed cars and trucks on the bridge just before impact.
The preliminary NTSB report also revealed that the Dali had suffered a blackout 10 hours before the collision during in-port maintenance. That blackout was triggered by a mistake by a crew member, the report said.
The connection between the earlier blackout and the one that preceded the deadly accident remains under investigation, the NTSB said in its report.
The report noted that just before the Dali departed the port, its captain told a local pilot assigned to guide the ship out of the harbor that the ship was in good working order.
Two tugboats assisted the Dali as it left the dock and moved into the harbor, then pulled away, according to the report. The pilot handed control of the ship to an apprentice, and not long after, the first blackout occurred. The senior pilot took back control.
An emergency generator restored power to the Dali, and the pilots called for help from a tugboat. The pilot ordered the anchor to be dropped. The pilot's dispatcher called police and the Coast Guard.
A second blackout then hobbled the Dali, and again, a generator restored power. But there was no propulsion to assist with steering.
One of the pilots got on marine radio to warn other boats. Police ordered the bridge closed to traffic, leaving only the roadwork crew on the span.
The Dali then hit the bridge.
It is rare for ships of that size to lose power and rarer still for it to happen in a narrow channel near the pillars of a major bridge. A last-minute mayday and quick actions on the ground most likely averted a much higher casualty count.
A weekslong search turned up the bodies of the six construction workers, that last of which was recovered May 7. The NTSB and the FBI opened investigations into the collapse. The city of Baltimore filed a legal claim against the Dali's owner, Grace Ocean Private Ltd., and its manager, Synergy Marine Pte Ltd., alleging negligence and full liability for the collapse.
In past statements, Synergy and Grace Ocean have expressed sympathy "to everyone affected and their families" but have declined to comment on the cause of the crash, noting the unfinished investigations and the ongoing legal proceedings. Maersk has said in statements that its "thoughts are with all parties impacted by the situation" but stressed that it neither owned nor operated the Dali. Maersk has said it would conduct an investigation of its own.
On Monday, precision explosive charges dismantled a span of the bridge that had come down on the container ship, finally freeing the vessel.
President Joe Biden has vowed that the government will help rebuild the bridge as soon as possible, as the Port of Baltimore is a major part of the Northeast economy and the busiest port for car imports and exports.
