Metro investigators say Friday's train derailment on the Green Line was likely caused by a misalignment of the rails, known as a "heat kink."
The incident occurred near the West Hyattsville station where three cars on the Green Line train derailed around 4:45 p.m., as the train entered a tunnel from an outdoor section of track. There were no reported injuries, and riders on the affected train evacuated safely, according to Metro officials.
The derailment shut down service between Fort Totten and Prince George's Plaza, causing significant delays for riders during the evening commute home. Shuttle buses substituted for trains in those areas.
Following the derailment, Metro imposed an immediate 35 mph speed restriction on trains operating in all above-ground territory, which caused delays on all other lines as well.
Heat kinks are short sections of misaligned track caused by the expansion of metal rails in extremely high temperatures. Metro officials say they are continuing to investigate whether any other factors were involved in the incident.
Green Line service between Fort Totten and Prince George's Plaza will remain suspended throughout the day Saturday as Metro crews work to repair the damaged track. During the maintenance, shuttle bus service will continue to operate between Fort Totten, West Hyattsville and Prince George's Plaza stations.
Track work on all other lines has been canceled this weekend.