Long Island Rail Road service resumed after a broken rail caused systemwide delays and cancellations at the height of the evening rush hour Wednesday.
The hours-long disruption frustrated commuters at Penn Station, already on edge as heat and humidity stifled the city on day four of the ongoing heat wave.
"I'm sweating," griped Diane Weiner of Huntington. "I usually take the 6:30, and there's no 6:30 listed here. I don't know what's going to happen."
"We just found out unfortunately once again, the train's not running on a hot, hot day in the summer," said Michelle Jaspan.
LIRR officials said service had to be suspended westbound between Jamaica and Penn Station, and delayed or canceled eastbound because of a broken rail in one of the East River tunnels.
Earlier, NJ Transit trains on part of the Northeast Corridor line were suspended because of sagging overhead power lines due to the heat. Service eventually resumed with delays.