Federal investigators say a captain's error led to a ferry crash that injured 80 people last year in Lower Manhattan.
National Transportation Safety Board investigators disclosed the findings Tuesday.
They say Jason Reimer "inadvertently" left the Seastreak Wall Street running on a seldom-used backup system.
Reimer switched to the backup after sensing a propeller vibration during the voyage from New Jersey. They say he failed to switch back as the vessel approached an East River pier.
Investigators blamed Seastreak for "ineffective oversight" and say Reimer's error was compounded by a lack of training.
The board also renewed a call to equip vessels with data recorders.
Seastreak did not immediately respond to a comment request.
A message left at a number listed under Reimer's name was not immediately returned.