A three-month safety investigation recently concluded that human error was responsible for the failure of an electric drive motor that removed the 188-car ferry Walla Walla from service. According to the final report, investigators determined the motor failure was avoidable and resulted from mistakes made by Washington State Ferries personnel. The motor failure occurred Nov. 4, 2012 when the Walla Walla was undergoing routine annual maintenance at Eagle Harbor Maintenance Facility on Bainbridge Island. • Communication between engine crew and maintenance staff was insufficient.