The Washington Metropolitan Area Transit Authority said deteriorating track conditions along the Orange and Silver lines caused a Metro train to derail on Friday.
Metro announced their preliminary findings in a statement about Surge 6 ridership on the first day of the SafeTrack program for Red Line riders.
The Metro safety department said two rails on which the trains run were too wide as a result of deteriorating rail ties. More than 450 rail ties were replaced in the area between Ballston and West Falls Church after the derailment.
Metro said there was no evidence of train operator error. The safety report also said car equipment, weather, temperature and other factors remain under review.
“While Metro and the outside experts continue their review, we are requiring supervisors to conduct a specialized track inspection to look for any other similar conditions that must be immediately addressed,” said Metro General Manager and CEO Paul Wiedefeld.
A six-car Metro train derailed Friday morning, injuring one rider and damaging two of the cars. The accident occurred near the East Falls Church Metro Station.
Service along the Orange and Blue lines was suspended until Monday morning to allow for inspection and clean-up of the derailment site. Shuttle buses were used to ferry passengers between the affected Metro stops.