Dali had four blackouts before crash into Baltimore Key Bridge, NTSB report shows

BALTIMORE -- The Dali, a 947-foot-long Singapore-based cargo vessel, lost electrical power hours before leaving the Port of Baltimore and crashing into the Francis Scott Key Bridge, according to a preliminary report released by the National Transportation Safety Board.

In a span of less than 12 hours, the ship experienced four blackouts before colliding with the central truss spans of the Key Bridge on March 26.

The report comes seven weeks since the disaster killed six construction workers, crippled the Port of Baltimore and cut access to the Beltway.

The preliminary report provided a synopsis of factual information collected during the on-scene phase of the investigation. A final report, which will include conclusions and safety recommendations, should come in one or two years.

You can read the full NTSB report here .

Sequence of events from the Dali crash

The preliminary report outlined the events leading up to the Dali striking Baltimore's iconic bridge.

The report revealed that the Dali initially lost power on March 25 during in-port maintenance, about 10 hours before leaving the Port of Baltimore. Vessel power was restored before a second blackout in-port followed, according to the NTSB report.

The vessel departed from the Seagirt Marine Terminal at the Port of Baltimore shortly after 12:30 a.m. en route to Colombo, Sri Lanka, carrying 4,680 containers.

The captain reported that the ship was in "good working order" and was assisted by two tugboats.

The ship then lost electrical power and experienced another blackout. The main propulsion diesel engine shut down automatically after the pumps lost electrical power, meaning the vessel's propeller stopped.

The Dali crew again restored electrical power.

The ship's crew called for tug assistance and the senior pilot ordered the anchor to be dropped. Then, a fourth blackout happened, according to the report.

A marine radio call was made to warn all waterborne traffic before the cargo vessel crashed into the central truss spans of the Key Bridge around 1:29 a.m.

Negative tests for alcohol and drugs

The pilots and crew members of the Dali were given a drug and alcohol test following the collapse of the Key Bridge.

Shortly before 3:30 a.m., the senior and apprentice pilots were replaced by another pilot from the Association of Maryland Pilots, and they were taken ashore where, at 5:30 a.m., they tested negative for alcohol and other drugs, per Coast Guard regulations.

Later, a third-party testing provider went aboard the ship to test the entire crew for alcohol and drugs, according to the report. All tested negative for both.

Hazardous materials onboard the Dali

Of the 4,680 containers on board the vessel at the time of the accident, 56 were identified as containing hazardous materials.

Those containers were located throughout the ship.

The NTSB identified 14 containers, which were recorded as containing hazardous materials, which may have been damaged when the ship struck the Key Bridge or during the subsequent collapse of the bridge deck onto the ship.

Explosives remove Key Bridge section from cargo ship

The removal of a 4,000-ton piece of the Key Bridge collapse from the Dali cargo ship using explosives unfolded successfully Monday evening and is a critical piece of the overall recovery.

Cuts were made in the steel where small explosive devices were placed and then were covered with what looked like heavy-duty tape. All were detonated within a few seconds.

The explosions sounded like fireworks and those within 2,000 yards were asked to wear hearing protection.

The U.S. Army Corps of Engineers called this process the "safest and swiftest" way to remove the thousands of tons of wreckage pinning the massive ship.

The controlled detonation sent the truss into the Patapsco River in pieces. Officials shared an animation of the process .

Through it all, more than 20 crew members remained onboard the Dali.

"They're staying on board because they're part of the ship. They are necessary to keep the ship safe and operational," said Rear Admiral Shannon Gilreath, from the U.S. Coast Guard.

Refloating the Dali

Colonel Estee Pinchasin, from the U.S. Army Corps of Engineers, said the next step is to remove the Dali from the crash site and open the channel. That is likely to take a couple of days.

"Once the wreckage falls into the channel, we will have the vessel refloated," Pinchasin said. "Our salvors already have the equipment ready to retrieve the wreckage just as we have over the last seven weeks."