A few minutes before the cargo ship Dali crashed into the Francis Scott Key Bridge early Tuesday, the vessel had a “complete blackout” that knocked out power to the engine and navigation equipment, an industry official said.

The official, Clay Diamond, the executive director of the American Pilots Association, said Tuesday that he had been speaking regularly with the Association of Maryland Pilots and that the cause of the system failure was unclear. Though the ship’s backup generators had kicked on, restoring some power, the propulsion system remained offline.