(The following article by Michael Luo was posted on the New York Times website on September 29.)
NEW YORK — It started with a single power line that somehow fell down. The line, one of a series of electrical wires that power trains and equipment, fell on another overhead wire along the railroad tracks that run from Queens into Pennsylvania Station in Manhattan.
That mishap on Monday afternoon, railroad officials said, set in motion the chain of events that brought the station to a standstill and disrupted the trip home for more than 100,000 commuters.
“You have an operation that is pretty much on the edge as far as the level of precision involved,” said Clark Hampe, Penn Station’s chief of operations planning. “You can’t really stand too many impediments.”
The crisis began just before 1 p.m. somewhere in Queens, according to the working theory that has emerged.
There, a signal cable, carrying more than 2,000 volts, came down on the overhead wire that provides electric power to trains at 11,000 volts.
Like a lightning strike, the contact between the two lines sent a surge of power down the line and into one of the four tunnels under the East River, setting off an explosion from a circuit breaker, overloading a transformer, knocking out power and leaving and an electrical fire and heavy smoke in its wake.
Unsure of exactly what was going on, officials inside the Penn Station Control Center, which is near the station, tried to restore power, said Clifford Black, a spokesman for Amtrak, which owns Penn Station. They were able to briefly, but then lost it again, confirming that there was a serious problem underground.
They were able, however, to bring in a train from Washington that was stranded inside a tunnel under the Hudson River.
Meanwhile, responding to a 911 call, firefighters arrived at New York University Medical Center at 33rd Street and First Avenue and found smoke billowing from an emergency exit shaft leading into the hospital from the East River tunnel, said Michael Loughran, a Fire Department spokesman.
A fire chief went halfway down the shaft, a narrow spiral staircase that winds 92 feet to the track bed, before retreating, Mr. Loughran said. After confirming that no passenger trains were stuck in the tunnel, they asked that power to all four tunnels under the East River be shut down.
This was a crippling blow for the Long Island Rail Road, the biggest user of Penn Station, and its riders were most severely affected by the problems. The railroad was unable to run any passenger trains into or out of Penn Station for hours during the afternoon and evening.
But because power was restored to tunnels under the Hudson River, New Jersey Transit and Amtrak were able to operate a limited number of trains, except for about an hour when the station was shut because of seeping smoke. Train schedules did not return to normal until yesterday afternoon.
“The Fire Department had to go down 92 feet below the surface in heavy smoke conditions,” said James Dermody, president of the Long Island Rail Road. “So, naturally, they’re going to be very careful and very cautious.”
Making sure that the wires and the electrified third rail in all four tunnels that feed Penn Station were neutralized was not so simple.
“It’s not like flicking a switch,” Mr. Loughran said.
Actually, turning the power off is relatively easy. Officials are able to do it from inside the station’s control center. But electricity can continue to radiate from wires, so they have to be grounded, meaning that a cable must be clamped to the wires and run to the track bed, draining the electricity away.
The initial report that came over to firefighters was that a transformer was on fire. Firefighters asked railroad officials to make sure that the transformers in the tunnels did not contain toxic chemicals, as some do. Fortunately, said Mr. Hampe of Amtrak, the railroad’s environmental officer was at the control center and could confirm that the transformers were not toxic. Firefighters also ran their own tests of the air in the shaft.
All of this took about three hours. In the meantime, firefighters also ordered that Penn Station be closed for about an hour because of worries about smoke and fire, railroad officials said. Riders who were already in the station were allowed to stay, but no one was else was allowed inside.
It was not until 4 p.m. that firefighters began their descent to the track bed, said Mr. Loughran of the Fire Department. Meanwhile, New Jersey Transit and Amtrak had resumed limited service out of the station.
Once firefighters got to the track bed of the tunnel, they found a relatively small fire, essentially some smoldering wires, Mr. Loughran said. The smoke was caused by the burned insulation around the wires.
Because it was an electrical fire, the firefighters used chemical extinguishers, and declared the fire out about 5:30 p.m. The tunnel, designated Line 2 by transportation officials, remained out of commission because of the damage. All three railroads normally use the tunnel, so all were affected. New Jersey Transit uses it to bring trains from a railyard in Queens, while the Long Island Rail Road and Amtrak send passenger trains through it.
Almost immediately after the Fire Department declared the tunnels safe, Long Island Rail Road officials sent a patrol train out through Line 4, another of the tunnels, because they got power back up and running there quickly, Mr. Dermody said.
But officials did not immediately restart service out of Penn Station. Instead, they decided to send trains to Jamaica to try to relieve the congestion there. Finally, about 6:30 p.m., a few Long Island Rail Road trains began running out of Penn Station.
By this time, however, the delicate choreography of trains had been disrupted beyond repair. Amtrak had been halting incoming trains in places like Philadelphia and New Haven, so it was short on equipment and crews. The Long Island Rail Road and New Jersey Transit had similar issues. Many New Jersey Transit trains were stuck in a railyard in Queens, while the Long Island Rail Road could not get to trains at a yard west of Penn Station.
Yesterday, after much improvising, New Jersey Transit and Amtrak had a mostly normal morning rush. The Long Island Rail Road had some delays and had to divert some trains that normally would have gone to Penn Station to Atlantic Terminal in Brooklyn and Hunters Point Avenue in Queens.
Finally, at 3:30 p.m., the damaged tunnel came back on line, and Penn Station was back to normal.