When trains along the busy Northeast Corridor lost power yesterday, there was no panic or pandemonium, passengers said – just the sound of everyone making calls on their cell phones.

“I called my wife at work,” Shane White, 33, a fixed-income analyst at Lehman Brothers stranded on his way from Chester, N.Y, said. “Everyone was just making small-talk on their cell phones. Nobody was upset. Frustrated maybe.”

Thousands of commuters in dozens of trains between Boston, New York, and Washington, D.C. were stranded for up to four hours when power along the corridor mysteriously went out at 8 a.m. Passengers on the stranded trains said they knew something was amiss when the air-conditioning stopped and the motors went quiet. The trains coasted on the tracks before coming to a subtle stop.

Five trains – three from New Jersey Transit, and two from Amtrak – were stranded in tunnels. Two were stuck under the Hudson. After two hours, the batteries in many of those trains ran out and passengers were left in near total darkness for another one to two hours.

“There was some ambient light coming from outside the train, but it was pretty dark,” Jonanthan Morris, 25, a package designer for Coty, said. “Everybody was pretty calm and making jokes.”

Mr. Morris said he used the blue light from his cell phone to read a fantasy fiction book and listened to his iPod to pass the time.

To make matters more urgent in the sweltering, crowded train cars, a pregnant woman went into contractions on one train stranded in the tunnel. Authorities said she was taken to a hospital a few hours after the outage without incident. Amtrak crews docked with at least two of the stranded trains and evacuated them 500 people at a time.

Power was restored by 10:30 a.m., officials said, but it took some trains another hour to get moving again.

Amtrak’s superintendent for New York operations, Tom Pyle, said the outage started at a provider outside Philadelphia, but officials said the cause was still a mystery yesterday evening.

Senator Schumer, a Democrat of New York, criticized the administration of Amtrak, which has three empty slots on its seven-person board.

“If there was ever proof that Amtrak is being terribly mismanaged with unqualified people at the helm, this power outage at the height of the morning rush hour is it,” he said in a statement. “It’s time to put experienced professionals in charge of Amtrak, it is clear that they are sorely needed.”

Mr. Pyle said there were about two-hour delays for most of the stranded trains. Metro North trains were unaffected by the power outage because they use a separate power supplier. A Metro North spokesman, Daniel Brucker, said Metro North provided free transfers to hundreds of stranded Amtrak customers. Metro North trains were running on time.

New Jersey Transit service was highly congested last night, with service cut down by a third along the Northeast Corridor and the North Jersey coastline.

All service on Amtrak and New Jersey Transit was expected to return to normal Friday morning, officials said.