HUNTINGTON, Utah - Seismic activity has 'totally shut down' efforts to reach six miners trapped below ground and has wiped out all the work done in the past day, a mine executive said Tuesday.
'We are back to square one underground,' said Robert E. Murray, chairman of Murray Energy Corp., owner of the Crandall Canyon mine.
Still, 'we should know within 48 to 72 hours the status of those trapped miners,' Murray said. Rescue crews are drilling two holes into the mountain in an effort to communicate with the miners - provided they are still alive.
Meanwhile, unstable conditions below ground have thwarted rescuers' efforts to break through to the miners, who have been trapped 1,500 feet below the surface for nearly two days, Murray said.
The seismic activity and other factors 'have totally shut down our rescue efforts underground,' he said.
'There is absolutely no way that through our underground rescue effort we can reach the vicinity of the trapped miners for at least one week,' Murray said.
The National Earthquake Information Center in Colorado said 10 seismic shocks have been recorded since the collapse, but only one since 3 a.m. Tuesday. That one struck at 3:42 p.m. with a magnitude of 1.7.
Murray has insisted the cave-in was caused by an earthquake. But government seismologists have said the pattern of ground-shaking picked up by their instruments around the time of the accident Monday appeared to have been caused not by an earthquake, but by the cave-in itself.
'Based on the information and preliminary analysis we've done so far, this event doesn't look like a natural event. It doesn't have the proper characteristics of a natural earthquake,' said Rafael Abreu, a geologist for the earthquake information center. 'Even though it's not a natural earthquake, it could still generate aftershocks, which is exactly what we're seeing in this particular situation.'
Murray lashed out at the news media for suggesting his men were conducting 'retreat mining,' a method in which miners pull down the last standing pillars of coal and let the roof fall in.
'This was caused by an earthquake, not something that Murray Energy ... did or our employees did or our management did,' he said, his voice often rising in anger. 'It was a natural disaster. An earthquake. And I'm going to prove it to you.'
Amy Louviere, a spokeswoman for the federal Mine Safety and Health Administration in Washington, said the men at the mine were, in fact, conducting retreat mining.
However, Louviere said that exactly what the miners were doing, and whether that led to the collapse, can be answered only after a full investigation.
Retreat mining has been blamed for 13 deaths since 2000, and the government requires mining companies to submit a roof control plan before beginning such mining. Such a plan details how and when the pillars will be cut and in what order.