Human Error Likely Caused Subway Crash and Derailings, Officials Say

A collision between two subway trains in Manhattan on Thursday occurred when a train carrying about 300 passengers was driven into the path of an out-of-service train because of confusion over which vehicle had the right of way, according to three transit officials with knowledge of the investigation into the crash.

The collision, which injured 26 people, caused both trains to derail, and continued to interrupt service on some of the busiest transit lines in the city a day later.

Human error appeared to have caused the collision, said the officials, who requested anonymity because they were discussing an active investigation. It was not immediately clear who was at fault. The officials said an error was made by the crew on the out-of-service train; the leader of one transit workers union suggested that the crash was caused by a supervisor.

The Metropolitan Transportation Authority, which operates the subways, and the National Transportation Safety Board are both looking into the collision. There were no serious injuries.

Jennifer Homendy, the chair of the N.T.S.B., said during a news conference Friday afternoon that 13 specialists are investigating the incident. They will be examining the performance of employees who were working in the trains as well as those in the subway system’s control center.

“It’s easy to blame humans,” Ms. Homendy said when asked if the crash was caused by a person’s mistake. “Human error is always a symptom of a system that needs to be redesigned.”

On Thursday, just before the afternoon rush hour, a No. 1 train — which travels the length of Manhattan’s West Side — stalled at 79th Street after vandals tripped the train’s emergency brakes, M.T.A. officials said at a news conference. The stalled train disembarked its passengers, went out of service and was slowly making its way to a storage yard farther uptown, according to the transit officials with knowledge of the investigation.

A crew of four transit workers was aboard the out-of-service train, which forced the rerouting of other No. 1 trains. According to the M.T.A. officials with knowledge of the investigation, near the 96th Street station, the subway’s signal system instructed the out-of-service train to stop at a red light and gave the green light for a rerouted train to go around it on parallel tracks then move back in front. The out-of-service train continued to inch forward, causing the slow-moving crash, the officials said.

One of the officials said that the authority’s investigation is focused on whether someone did not follow protocols. The officials said that there was a miscommunication, but investigators have not yet determined who was at fault.

Addressing reporters on Friday, Richard Davis, the president of the Transport Workers Union Local 100, said that people in management were “controlling the train.”

One derailed car from the train that had been carrying the passengers and another from the out-of-service train were still stuck in a subway tunnel near 96th Street on Friday as crews worked to get them back on the rails.

The stuck car from the passenger train is in a low-height area, making it difficult to mount it back on the rails, said Janno Lieber, the chairman of the M.T.A. The wheels came off the front car of the out-of-service train, making it difficult to move, M.T.A. officials said on Friday.

Subway service was suspended on the 1 and 3 lines between Times Square and Harlem, a stretch that includes some of the most congested stations in the heart of the city. There was no service on the 2 line on the West Side. Though M.T.A. officials had hoped to restore service on Friday, the agency noted that the suspensions would remain in effect at least through the day. Extra buses were deployed to carry passengers up and down the West Side. A combined 870,000 passengers ride the 1, 2 and 3 lines on an average weekday.

Subway derailments involving passengers have been rare in recent years. The last one occurred on Sept. 20, 2020, when an express train came off the tracks around 14th Street with 100 people on board. Three passengers suffered minor injuries.

On Thursday, firefighters and M.T.A. workers helped roughly 300 people evacuate the train carrying passengers involved in the collision plus another 300 to 400 passengers on a train that was running behind it, after cutting off power in the station.