TALLMANSVILLE, W.Va. – Rescue crews found one body late yesterday in a West Virginia mine where 13 miners were trapped after an explosion, according to the miners’ family members. Late last night, family members said the other 12 miners are alive.

John Groves, whose brother Jerry Groves was among the trapped miners, said Governor Joe Manchin had announced that rescuers found one body in a mine car.

A Red Cross volunteer, Tamila Swiger, who was inside the Sago Baptist Church, said family members were “passing out and crying and just really in bad shape” after hearing about the body.

The body was not identified.

The miners were trapped 260 feet below the surface of the Sago Mine, about 100 miles northeast of Charleston, after an explosion early Monday.

Company officials have refused to speculate on the cause of the blast, but the governor’s office said it might have been caused by lightning.

Sandy Barron, whose nephew Randal McCloy was one of the trapped miners, said families had been told there was no trace of the other men. Families were still hopeful that they made it to safety.

The body was found in a mine car that was undamaged. It was unclear where the car was located. Families hoped the undamaged car meant the other miners may have been able to escape unharmed.

“That’s a good thing. There’s a very good chance they’ve barricaded themselves somewhere,” John Groves said. “They don’t know where they went, but they went somewhere.”

Earlier yesterday, the prospects of finding any of the miners alive appeared bleak after holes drilled into the ground yielded deadly levels of carbon monoxide and no signs of life.

“With each hour that passes, the likelihood of a successful outcome diminishes,” the chief executive of mine owner International Coal Group, Ben Hatfield, said.

By early evening, Mr. Hatfield said, rescuers were three to five hours from reaching the spot where the miners were thought to be.

“We are clearly in the situation where we need a miracle,” he said.”But miracles happen.”

The men were believed to be about 12,000 feet past the opening of the shaft. By early evening, about 35 hours after the blast, rescue teams had penetrated 11,400 feet, working their way on foot for fear machinery might cause volatile gases to explode.

The company told families that a powerful explosion had rocked the mine, based on damage near where the miners may be trapped, said Rick McGee, who works at the mine with Mr. McCloy, his brother-in-law.

Cinderblock walls meant to direct the flow of air inside the mine were knocked down by the blast, Mr. McGee said.

Given the new information, Mr. McGee said, “There’s a chance, not a great chance,but there is still a chance” that the miners could still be alive.