An investigation found that a loose screw caused a Portland Streetcar crash on May 24.

The crash happened at 1:10 p.m. when a streetcar collided with two vehicles at Southeast Grand Avenue at Taylor Street. A third vehicle was also damaged. The streetcar derailed as a result of the impact with one of the vehicles.

One person was injured and taken to an area hospital.

Story Continues Below

Portland Streetcar officials said at 1:07 p.m. the operator reported to dispatch that the master controller's motoring drum handle "deadman" function was sticking in the engaged position and was over-rotating past its usual stopping point. The operator unloaded the streetcar at the Southeast Grand and Hawthorne location and then continued to the maintenance facility, but the master controller became stuck in propulsion mode and the deadman function was inoperative. The operator was unable to stop the streetcar.

Officials did say the operator sounded the horn before the crash.

An investigation the next day found that a screw in the assembly of the streetcar's master controller came loose and lodged in the handle mechanism, preventing the operator from stopping.

Officials say they have contacted the manufacturer of the master controller assembly for help maintaining the component.

Portland Streetcar, along with TriMet and the Oregon Department of Transportation Rail and Public Transit Division, are continuing to investigate the collision.

Copyright 2018 KPTV-KPDX Broadcasting Corporation. All rights reserved.