The extensive container vessel that caused the Francis Scott Key Bridge to collapse had experienced power failures twice before departing from the Port of Baltimore, according to a preliminary report from the National Transportation Safety Board (NTSB) released on Tuesday.
The NTSB has been investigating the collision, which resulted in six deaths and the destruction of critical infrastructure, since it occurred in the early morning hours of March 26. The report provides the first official account of the events leading up to the disaster and its immediate aftermath.
Approximately 10 hours before leaving the port, the container ship named Dali suffered a blackout during maintenance when a crew member accidentally closed an inline engine exhaust damper, blocking the engine's exhaust and causing it to stall. The crew restored power by manually closing two breakers, but a second blackout occurred due to insufficient fuel pressure in one of the ship's generators. The crew successfully restarted the generator by reopening its exhaust damper.
"While recovering from this second blackout," the report notes, "the crew switched the ship’s electrical configuration to use a different set of breakers than what it had been using for the past several months." It was these new breakers that were in use when the ship departed hours later.
The Dali left the port at 12:36 a.m., assisted by two tugboats and a pair of pilots from the Association of Maryland Pilots. Nine minutes later, the senior pilot ordered the tugboats to be let go, and the Dali was navigating the channel under its own power.
Less than an hour later, at 1:25 a.m., the two electrical breakers that supplied most of the ship’s power tripped, causing the first blackout offshore and resulting in the shutdown of the main engine and steering mechanism. At that moment, the Dali was 0.6 miles away from the bridge.
The voyage data recorder was also affected by the blackout and stopped recording the ship’s system data for about one minute, although it had continued to record audio.
"The Dali crew was able to restore electrical power to the vessel," the report said, "but, when the ship was 0.2 miles from the bridge, a second electrical blackout occurred," causing a total loss of vessel electrical power. One of the pilots on board had already alerted a dispatcher on shore, and the dispatcher was able to notify the Maryland Transportation Authority police, which closed the bridge to traffic.
Seven road maintenance workers and one inspector were still on the bridge when the ship struck. The inspector was able to run to the nearest surviving span before the bridge collapsed and survived. All the maintenance workers, who were in their vehicles at the time, fell into the Patapsco River along with the bridge. One of the workers was able to free himself from his truck and survived with injuries. The rest died.
A crew member on the Dali also sustained minor injuries fleeing debris when part of the span fell on top of the ship.
The report does not comment on whether the first set of power outages or the crew’s efforts to fix them were related to the second set of power outages once the ship was sailing.
“We have to wait for a more detailed inquiry to see if it was related at all to it,” said Capt. Ashok Pandey, a master mariner and associate professor of maritime business at the Massachusetts Maritime Academy, who reviewed the NTSB report at the request of USA TODAY.
Pandey said it’s standard operating procedure to perform a thorough test of the ship’s controls and its main engine shortly before departure. Though the test isn't mentioned in the NTSB report, Pandey said the test’s findings would have been logged and any major problems communicated to both the ship’s owner and management company.
The ship’s top commanders probably “didn’t feel there was anything that would prevent the ship from sailing,” Pandey said. “So I’m not reading too much into it, unless an inquiry finds there was something amiss that was missed by all that could have contributed to the engine blackout.”
Regardless of what caused the blackout, Pandey said, he believes the disaster could have been averted, or at least minimized, had the Dali used tug escorts all the way through the channel and out to sea.
“That’s the glaring human error here,” he said, referring to the lack of mandatory tug escorts. “It’s a larger problem that the industry has to deal with here.”
The NTSB report confirms what the Associated Press had reported in April – that the Dali had suffered apparent electrical issues before it left port, which was based on information from an anonymous source. The city of Baltimore repeated that information in a lawsuit it filed last month against the ship’s owner and manager for damages related to the incident.
The city also argued that neither the ship’s owner, Grace Ocean Private Ltd., nor its manager, Synergy Marine Private Ltd., should be allowed to limit their liability in the case, claiming both had failed to properly train and supervise the crew, failed to follow safe work and operational procedures, and failed to properly maintain, equip, and inspect the vessel.
Grace Ocean and Synergy have been participating in the investigation, along with other agencies, associations, and companies. The FBI separately has been investigating the incident, the agency confirmed last month.
A spokesman for Synergy Marine, Darrell Wilson, confirmed the company’s involvement in the investigation but declined further comment “out of respect for the investigations and any future legal proceedings.”
“We again extend our deepest sympathy to all of those impacted by this incident,” Wilson said in an email to USA TODAY.
In addition to detailing the power outages leading up to the bridge collision, the NTSB report ruled out two other potential factors in the disaster – substance use and fuel problems.
The ship’s entire crew underwent drug and alcohol testing less than an hour after the crash and again a few hours later, per U.S. Coast Guard regulations. All tested negative.
Both pilots also were administered drug and alcohol tests once they got back ashore. Those, too, were negative, the report said.
At the time of the incident, the Dali was burning low-sulfur marine gas oil procured from Newark, New Jersey. Testing of that fuel determined that it complied with international standards and regulations and raised no concerns about its quality.
Several marine experts had speculated that dirty fuel – a common problem in commercial vessels and one that can gum up an engine – could have played a role in the ship's power outage. The report's findings say otherwise.
The NTSB said that its work continues. For example, the report noted, its investigators are still examining the Dali’s propulsion and electrical system, analyzing and validating its voyage data recorder and have planned interviews with numerous stakeholders.
The agency also is assessing other bridges to see if they need improved pier protection. It specifically named the Gov. William Preston Lane Jr. Memorial Bridge – also called the Bay Bridge – near Annapolis, Maryland, as one such bridge.
“Planned areas of investigation,” the report said, “include oceangoing vessels’ propulsion and electrical systems; the frequency and causes of vessel contacts with bridges over navigable waters; and bridge-strike mitigation measures such as a combination of vessel-size restrictions, vessel-assist tugs, and bridge-pier protection.”