Rescuers found no signs of life after drilling a fourth hole into a collapsed mine where six workers have been trapped for nearly two weeks, a disheartening blow in a rescue effort that has killed three other people.
A microphone lowered into the new hole on Saturday revealed nothing to indicate that anyone was in the cavern, and attempts to communicate with the miners by tapping on a drill bit yielded no response, a US Mine Safety and Health Administration (MSHA) official said. A video camera was being lowered into the hole overnight.
Underground tunneling had been halted after a mountain "bump" on Thursday killed three rescuers and injured six others. Officials had hoped a fourth hole drilled into the mine would finally offer clues to whether the men were alive 450m below ground. Instead, the results were the same as the three previous tries.
"We did not detect any signals from miners underground," said Richard Stickler, head of MSHA.
Crews spent at least four hours beating on the drill steel and setting off explosives to try to get the miners' attention, he said.
Stickler said a fifth hole was planned.
"As long as we have hope, we will continue working and doing everything we can. Our goal is to find these miners alive," he said.
Rob Moore, vice president of Murray Energy Corp, co-owner of the Crandall Canyon mine, remained optimistic.
"Make no mistake about it: This continues to be a rescue effort," he said. "We have encountered setbacks. We've incurred losses, but we have not and will not give up hope."
Even if rescuers find signs of life -- an increasingly unlikely prospect, given the amount of time elapsed -- it would take weeks to lift them out.
Crews would have to drill a much larger, 76cm hole and lower a metal rescue capsule, the same method used in 2002 to pluck nine trapped miners from the flooded Quecreek mine in western Pennsylvania.