Naoma, West Virginia (CNN) - Rescue crews seeking four miners missing after an explosion in a West Virginia coal mine were pulled from the mine Thursday because deteriorating air quality posed the threat of a new blast, officials said.
The crews were ordered to turn back about 9:30 a.m., said Kevin Stricklin of the U.S. Mine Safety and Health Administration.
As the rescuers - 32 in all, in four teams - were in the mine, officials began to get deteriorating readings on air exiting a borehole drilled into the mine Wednesday, Stricklin said.
"We do not base pulling people on one sample," he said. "We looked at a couple of samples. They were all very consistent."
The readings showed levels of carbon monoxide, methane and hydrogen rising to potentially explosive levels, endangering the rescuers. FULL STORY