Cargo ship had multiple blackouts before striking Baltimore bridge, investigators find

The ship that knocked down Baltimore’s Francis Scott Key Bridge suffered two electrical blackouts the day before the collision and later experienced two more blackouts that disabled critical equipment, federal safety investigators said in a preliminary report released Tuesday.

The report, issued by the National Transportation Safety Board, provides the first detailed examination of what went wrong as the Singapore-flagged cargo ship Dali lost power, veered off course and slammed into a critical bridge pier. It lays out a comprehensive timeline of the events leading up to and immediately following the crash, describing in technical terms a rapid-fire series of problems before the Dali struck the bridge, though it says investigators are still exploring precisely what caused some of the failures.

The cause of the crash - which killed six bridge workers, halted most trade at the Port of Baltimore and raised questions about whether federal and state authorities are prepared to prevent similar tragic disruptions in the future - is likely to be scrutinized for months and years to come.

The FBI has launched a separate criminal investigation focused on the Dali, including whether the crew knew of serious system problems before setting out in the early morning darkness on March 26. Dozens of law enforcement officials boarded the Dali, which until Monday had been pinned beneath a vast section of the fallen bridge, on April 15 to search for evidence. Attorneys representing the city of Baltimore and a local business executive have filed separate complaints in federal court in Maryland against the Dali’s owner and manager, alleging negligence before the crash.

The NTSB’s findings suggest the ship had mechanical issues - though the agency did not indicate whether its investigators believed crew members or the ship’s owners had done anything wrong that led to the bridge strike.

A spokesperson for the Dali’s owner, Grace Ocean Private Ltd., and its manager, Synergy Marine Pte Ltd., both based in Singapore, did not respond to a request for comment. In court, the companies have asked a federal judge to limit their liability in the tragedy to about $43.6 million.

The day before the disaster, as the Dali prepared to leave the Port of Baltimore for a voyage to Sri Lanka, the ship lost power twice, investigators said in the report. Officials wrote that a mistake by a crew member working on part of a diesel engine caused an initial “in-port blackout.” A second blackout in port “was related to insufficient fuel pressure,” it said.


“The NTSB is still investigating the electrical configuration following the first in-port blackout and potential impacts on the events during the accident voyage,” the report said.

Just after midnight on March 26, an Association of Maryland Pilots senior pilot and an apprentice pilot boarded the Dali. As part of standard procedure, the senior pilot asked the Dali’s captain about the ship’s condition - and the captain said the vessel was in “working order,” according to the report.

Two tugboats pulled the Dali away from the dock and guided it out of port, the report said. About 30 minutes later, the pilot ordered the tugs to pull away, per standard protocol. Within about 15 minutes - when the Dali was roughly half a mile from the Key Bridge - two electrical breakers that feed most of the ship’s equipment tripped “unexpectedly,” knocking out power to the Dali, the NTSB said.

The outage cut power to a series of vital pumps, automatically shutting down the ship’s main engine.

The Dali’s crew was able to restore power. They called for tug boats to help, and a senior pilot ordered an anchor dropped. Then, according to the NTSB, came the second blackout on the day of the crash.

A warning call went out. But soon thereafter, investigators said, the Dali hit the bridge while traveling at 6.5 knots.

Aside from the those identified in the report, NTSB investigators wrote that they were not aware of any other Dali power outages while the ship was in port in Baltimore or earlier in Newark and Norfolk. The local pilots and Dali crew were tested for drugs and alcohol, and the tests came back negative, the report said. The Dali’s fuel was also tested, investigators said, but no issues were identified.

The NTSB said the Dali’s initial power outage stopped the vessel’s steering pumps, leaving the rudder “unable to be moved” for a period of time. Its experts are still investigating when an emergency generator started up, which would have been able to power an emergency steering pump, allowing the rudder to move again. But “without the propeller turning, the rudder would have been less effective,” the NTSB said.

The report describes the protections that were installed when the bridge, which opened in 1977, was built. They included four pier-protection barriers, known as dolphins, that were made of concrete and were 25-feet in diameter. They also included 17-foot-long rubber fenders around the dolphins.

But the errant Dali easily slipped past those modest barriers. Two of the piers themselves were also surrounded by a “crushable concrete box and timber fender system” that measured approximately 100 feet by 85 feet, according to the NTSB. But the fendering system made no difference as the Dali knocked down the pier, and with it the rest of the bridge.

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Federal bridge design specifications requiring pier protections for new bridges were first put in place in 1994.

Investigators said NTSB officials are working with the Maryland Transportation Authority to study short- and long-term upgrades to the current protection systems for the Bay Bridge near Annapolis. Officials are also examining pier protection improvements that were made after several other major bridge collapses caused by ship strikes, including at the Sunshine Skyway Bridge in Tampa Bay, Fla.; Queen Elizabeth Causeway Bridge near South Padre Island, Tex.; and I-40 Bridge near Webbers Falls, Okla.

NTSB chair Jennifer Homendy previously said investigators have been working with technicians from Hyundai, which manufactured equipment in the engine room, to retrieve data related to the electrical failure. Homendy is scheduled to testify before Congress on Wednesday during a hearing with other key federal agencies working on the Key Bridge investigation, clean-up and reconstruction plan.

Investigators said in the preliminary report that they plan to continue probing “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.”

The ship’s voice data recorder captured voices - at varying degrees of quality - from the Dali’s deck and from radio traffic. NTSB officials have mined those recordings and interviewing key crew members to get a fuller picture of the events leading up to the collision.

Beyond the mechanics of what failed aboard the Dali, federal marine safety investigators are also seeking to understand what may have gone wrong in the broader system meant to keep ships passing safely under critical U.S. infrastructure, an everyday occurrence that is fundamental to local economies and global commerce.


There are numerous cases when ships lose the ability to move themselves through the water. A Washington Post analysis of Coast Guard records found that hundreds of large ships have lost propulsion, many near bridges and ports. In 2021, a container ship lost propulsion for 15 minutes shortly after traveling under the Key Bridge, according to the records.

Under U.S. maritime law, prosecutors can bring charges against the owner, captain or crew members of a ship under what is known as the seaman’s manslaughter statute if they are deemed responsible for an incident that resulted in death. Before that, though, federal officials will have to prove criminal negligence.

Another issue that could be a subject of the ongoing NTSB investigation is whether the two power failures in port may have required notification to the Coast Guard before the ship set sail, said attorney James Mercante, head of the admiralty division at the law firm Gallo Vitucci Klar LLP.

Under federal regulations, those responsible for a vessel must immediately report anything that affects a vessel’s seaworthiness to the Coast Guard and then complete an incident form within five days. The question of “seaworthiness” is also at the core of the civil complaints filed in federal court.