WASHINGTON (AP) — Metro officials says new Silver Line tracks don’t appear to have been damaged in an incident during testing that caused major rush hour delays.

Metro spokesman Dan Stessel says there is no evidence that the train derailed Tuesday morning and the cause of the incident is under investigation. The transit agency says crews were running a train to test equipment near the East Falls Church station, where the new line to Dulles airport will break off from the Orange Line.

The Washington Post reports that Metro employees said a brake locked a train wheel and the crew was trying to return the train to a rail yard when a part broke loose and cut cables for signaling equipment.

(Copyright 2013 by The Associated Press. All Rights Reserved.)