A day after a subway train derailed in Manhattan, two supervisors who oversaw track work on the route were suspended as the Metropolitan Transportation Authority came under scrutiny for its safety performance.
A piece of rail that was left unsecured in the subway tracks caused the derailment on Tuesday, officials at the authority said Wednesday. The accident injured 34 people and prompted fears among subway riders that a system that has become increasingly unreliable might also be dangerous.
Subway officials blamed the derailment on human error and suspended the two supervisors without pay. But union leaders defended subway workers and argued that the authority must review its track procedures and safety culture.
The authority’s new chairman, Joseph J. Lhota, said that storing equipment between the tracks was a common practice in the railroad industry in order to make repairs more quickly. But the piece of rail that caused the derailment was short enough that it should have been removed from the site.
“The rules are the rules, and they didn’t follow the rules,” Mr. Lhota said in an interview on Wednesday.
The night before the derailment, workers replaced a piece of track on the Eighth Avenue line in Manhattan near the 125th Street station. They used 26 feet of rail from a piece that was 39 feet long.
The leftover 13-foot piece was left in the tracks to be picked up, even though the agency mandates that any piece of rail that is shorter than 19 feet 6 inches must be removed, Mr. Lhota said.
“The first thing we did — we started yesterday afternoon — was to evaluate the entire system to make sure there were no other pieces like this on the system,” Mr. Lhota said.
New York City’s subway has for decades stored such equipment in the tracks, using a rail spike to fasten the rails to the wooden railroad ties, said John Samuelsen, the president of Transport Workers Union Local 100, which represents subway workers. The rails are left in the tracks until a train can pick them up and take them to a rail yard — a decision that is made high above the level of subway workers.
“The decision not to have the rail collected by a work train was a decision by management,” Mr. Samuelsen said. “It is oversimplifying the tragedy by calling it just human error on the part of the supervisors.”
The subway in Washington also stores rails on the tracks, said Dan Stessel, a spokesman for the Washington Metropolitan Area Transit Authority, but he cautioned that it was important that they be properly secured. Amtrak no longer allows for replacement rails to be stored in the track area on the Northeast Corridor, said Mike Tolbert, a spokesman for Amtrak. The practice is allowed on Amtrak routes outside the Northeast, although speed restrictions are imposed in those areas.
As subway delays have skyrocketed in New York, Gov. Andrew M. Cuomo, who oversees the system, has faced growing pressure to address the problems. On Wednesday evening, a group of transit advocates held another rally outside his office in Manhattan to urge him to “fund and fix” the subway.
Mr. Lhota, who was named chairman last week, said he was working to restore confidence in the system. The agency was to hold a competition on Thursday soliciting ideas from transit experts around the world about improving service — a proposal made by Mr. Cuomo last month. The authority is seeking ways to improve the subway’s antiquated signals and to quickly buy more trains; winning proposals could earn a $1 million prize.
Asked about the pressures of serving as chairman while still a senior vice president at NYU Langone Medical Center, Mr. Lhota said he planned to hire an executive director who would manage daily operations so that he could focus on the agency’s “strategic direction.”
There had been no question that he would visit the scene of the derailment on Tuesday, he said.
“As the agency head, it’s my responsibility to be there,” said Mr. Lhota, who had planned to unveil a new subway station in Lower Manhattan that was flooded by Hurricane Sandy in 2012 but instead went to the station where the train derailed. “I left as soon as I heard about it.”
Mayor Bill de Blasio has faced criticism for not taking a more active role in focusing on the subway’s failures. On Wednesday, the mayor said he understood riders’ frustration and praised Mr. Cuomo’s decision to hire Mr. Lhota, who helped bring back the subway after Hurricane Sandy, during his previous tenure as chairman.
“Now we got to get to work — all of us — on a plan to address this immediate crisis,” Mr. de Blasio said in a radio interview on CBS 880.
In another radio interview, on 1010 WINS, Mr. de Blasio said a proposal by a state lawmaker to tax millionaires to raise money for the subway was “worthy of consideration.”
Michael Carrube, the president of the Subway Surface Supervisors Association, which represents the two supervisors who were suspended, said that the authority had not done enough to improve safety on the subway and that it was unfair to suspend the employees so quickly.
“It’s horrendous to point the finger and take someone out of service prior to the completion of the full investigation,” he said.