NEW YORK -- A crude firebomb engulfed a subway car in flames after it pulled into a heavily traveled station in lower Manhattan yesterday, burning more than 40 passengers in a few horrifying seconds and disrupting subway service to Brooklyn for hours.
Law enforcement officials said the firebomb, a mayonnaise jar filled with a flammable liquid, ignited, perhaps accidentally, in a crowded car on a No. 4 train on the Lexington Avenue IRT.
They said the device appeared identical to one that injured two teen-agers on another subway line Friday.
The officials said last night that they had a suspect in both incidents.
The man, identified by police as Edward Leary, 49, was burned over 85 percent of his body.
Officials said that he fled yesterday's inferno by sprinting through a dark subway tunnel to Brooklyn, and that he was found in a Brooklyn subway station and taken to New York Hospital-Cornell Medical Center, where he was being questioned detectives last night.
Former neighbors in an apartment building where Mr. Leary had once lived described him as unusually hostile and aggressive.
Residents of the building in Brooklyn said he used to distribute leaflets denouncing members of the co-op board and brought a toy machine gun to board meetings. They said he aimed it at board members he disagreed with and pretended to fire at them.
In the frightening moments after the explosion yesterday, passengers tumbled out of the blazing subway car, clothes and hair ablaze.
Some rolled on the concrete platform in the Fulton Street station, trying to put out the flames.
Authorities said 11 victims were taken to New York Hospital-Cornell Medical Center, five to Beekman Downtown Hospital, nine to St. Vincent's Hospital and six to Bellevue Hospital.
Four were said to be in critical condition; the others were being treated for burns of varying severity.
Soon after the explosion, officials appeared confident that the incendiary device had not been detonated by a terrorist.
But the blast sent jitters through a neighborhood with memories of the World Trade Center bombing in February 1993.
In front of Trinity Church on lower Broadway, where George Washington was sworn in as president more than 200 years ago, the cacophony of a busy afternoon was replaced by screams and sirens.
Police used 18th-century methods to control the 20th-century crowd that quickly gathered: Officers on horses kept onlookers behind police lines.
Some passengers emerged from exits and staggered into delicatessens, clothes sooty and hands blackened, demanding change for dollar bills so they could call relatives or 911.
Below, in the station, a haze of light smoke drifted across the platform.
"The train just lit up," said Ozell Lucas, a transit worker fixing a turnstile who watched in horror as the southbound train caught fire. "The flames were shooting out from the doors."
Witnesses described two explosions in rapid succession.
"In a split second I heard a boom and in another second I heard a second boom," said James Nobles, a token-booth clerk at the station who hit the booth's emergency button that summons the police.
Transit officials said the station had suffered no structural damage.
But the incident crippled operations at the cavernous station, a major transfer point for Brooklyn-bound passengers switching from the IRT to the IND.
Transit officials said that the fire occurred in the same car the conductor was riding in.
From the scorch marks, the firebomb appeared to have gone off under the seats near the front of the car across from the conductor's booth, said Jared Lebow, a spokesman for the Transit Authority.
Officials said an off-duty transit officer on his way to choir practice was sitting 15 feet away.
The officer, identified as Denfield S. Otto, 54, of Manhattan, ran to the token booth, grabbed a fire extinguisher and rushed back to the car to fight the flames.
Officer Otto, who is a 25-year veteran of the transit police and works the midnight shift, was immediately commended by everyone from Mayor Rudolph W. Giuliani to President Clinton.
But the officer said he did not feel like a hero.
"I was doing my job," said Officer Otto, who was on vacation this week and was 45 minutes late to a Transit Police choir practice.
A senior Police Department official, who spoke on condition he not be identified, said Mr. Leary had told detectives he was traveling around Manhattan looking for a job at the time of the explosion.
He said that just before the device went off, he accidentally dropped a resume into a bag belonging to a passenger next to him.
The official said Mr. Leary maintained that the blast occurred when he reached into the bag. "He's trying to suggest that the bag was left there and was not his," the official said.