“We are concerned about other transit agencies in the United States,” Ms. Homendy said. “We may at some point issue an urgent recommendation, or I’d say if you’re a transit agency operating in the United States and you’re listening, make sure that you’re checking your cars as well.”
The N.T.S.B. learned of the alignment failures from Washington’s transit authority only after the federal agency opened its investigation into last week’s derailment, Ms. Homendy said.
In a statement on Monday afternoon, Metro’s general manager, Paul J. Wiedefeld, said that the transit authority was “working hand-in-hand” with federal investigators and the Washington Metrorail Safety Commission, the independent agency that oversees safety in the Metro system.
“I want to assure our customers that their safety is driving every decision being made,” Mr. Wiedefeld said. “We apologize for the reduced service, and ask for our customers’ continued patience and support as we work to get Metro back to normal operations.”
Kawasaki Rail did not immediately respond to a request for comment on Monday.
There were 187 passengers aboard a blue line Metro train when it derailed at 4:51 p.m. on Oct. 12, just south of the Rosslyn station in Arlington, Va., according to federal investigators. The passengers were evacuated, and one person was taken to a hospital with non-life-threatening injuries, investigators said.
A preliminary N.T.S.B. investigation found that the same train had derailed at least twice before that same day, at 3:23 p.m. and 4:13 p.m., but the train “rerailed” itself because of the way the track was laid out in the other two locations.
Federal investigators said that they found broken sections of a brake disc where the two earlier derailments occurred. The car responsible for the derailment was four cars back from the motorman’s cab, Joe Gordon, the N.T.S.B. official in charge of the investigation, said on Monday.