A third rail fire stranded an LIRR train for two hours Wednesday afternoon, and led to rush-hour cancellations, authorities said.
It began about 1:15 p.m. in one of the four East River tunnels, according to an LIRR spokesman.
The power had to be shut off so that firefighters could extinguish the flames, but a Penn Station-bound train from Babylon was stranded.
A diesel locomotive pulled it out about two hours later.
Fourteen trains from Penn Station to Long Island were cancelled, and service from Jamaica to Penn Station was suspended until about 5:10 p.m., when a train from Huntington was the first to use the tunnel again.
Repair work on the tunnel has since finished, and normal service is being restored.
Penn Station became so crowded that the Eight Avenue entrance was shut down, but it has since opened.
A New Jersey Transit train also caused overcrowding at Penn Station during rush hour, when a 5:43 p.m. Morris & Essex line train became disabled near the platform.
It was not immediately clear what stopped the train.
There were delays of 20 minutes for New Jersey Transit riders coming in and out of New York City, a spokesman said.