BALTIMORE — Investigators working to pinpoint the cause of Baltimore’s Francis Scott Key Bridge collapse discovered a loose cable that could have caused electrical issues on the Dali, the massive cargo ship that lost power and disastrously veered off course before striking the bridge.

When disconnected, the problematic cable triggered an electrical blackout on the ship similar to what happened as it approached the bridge on March 26, according to new documents released Wednesday by the National Transportation Safety Board.

The documents don’t include any analysis or conclusions, which will be released later in the board’s final report. A spokesperson for the board declined to comment as the investigation is ongoing.

Investigation

The Dali was leaving Baltimore bound for Sri Lanka when its steering failed, because of the power loss. It crashed into one of the bridge’s supporting columns, destroying the 1.6-mile span and killing six members of a roadwork crew.

Safety investigators released a preliminary report earlier this year that documented a series of power issues on the ship before and after its departure from Baltimore. But the new records offer more details about how its electrical system may have failed in the critical moments leading up to the deadly disaster.

The Dali first experienced a power outage when it was still docked in Baltimore. That was after a crew member mistakenly closed an exhaust damper while conducting maintenance, causing one of the ship’s diesel engines to stall, according to the earlier report. Crew members then made changes to the ship’s electrical configuration, switching from one transformer and breaker system — which had been in use for several months — to a second that was active upon its departure.

That second transformer and breaker system is where investigators found the loose cable, according to investigative reports.

Investigators also removed an electrical component from the same system for additional testing, according to a supplemental report released in June. They removed what is called a terminal block, which is used to connect electrical wires.