Mine exec: Seismic activity has interrupted mine rescue effort

Speaking to reporters this morning, Murray held up a University of Utah Seismograph Stations report that he said proves his stance. He claimed the earthquakes lasted several minutes.

He said the epicenter of the 3.9 magnitude quake was too far away from where the miners were trapped to say, as it's been reported, that a mine collapse caused the earth to rumble.

However, seismologists at the University of Utah said preliminary reports indicated that the seismic "event" was caused by the mine collapse. "The preliminary results are consistent with a mine collapse as the source of the seismic wave that we recorded," said seismologist Relu Berlacu. "However, at this time we don't rule out the event of an earthquake."

Berlacu said they did record several "aftershocks" measuring up to 2.0 on the Richter scale within the area, but said that could also be consistent with a mine collapse.

The Mine Safety and Health Administration said there will be an "exhaustive" investigation to determine what caused the collapse.

Stickler would not speculate on the cause of the mine collapse or whether so-called retreat mining had anything to do with it.

"I assure you, by the end of that investigation, we will have the answer," he said.

MSHA officials in Washington, D.C. confirmed to the Deseret Morning News tonight that the Crandall Canyon Mine had been doing retreat mining. A plan filed by the mine was approved in June 2007, said MSHA spokeswoman Amy Louviere.

"What we have emphasized that as long as the roof control plan is followed, it can be a very safe method for mining," she said.

Murray also lashed out at some news media outlets for seeking comment from union leaders — "lackeys" as he called them — he alleged were trying to unionize the non-union Crandall Canyon Mine. Clearly irritated by a news helicopter flying overhead, Murray halted his morning news conference to demand the Emery County sheriff get the helicopter removed.

Rescue equipment arrives

Ten miners were in the middle of a 12-hour shift early Monday morning when a mine shaft collapsed, trapping six of the men. The other four were able to escape and are now helping in rescue efforts. It's believed the six miners are trapped 1,500 feet underground, 2,000 feet from the nearest access and nearly 4 miles from where they entered the mine.

The U.S. Air Force flew in sonar equipment overnight to Grand Junction, Colo., as part of a process to search for signs of life in the mine. It's expected that dynamite charges will be set off some distance away from the six remaining miners � who have been trapped by a collapse in the mine since just before 3 a.m. Monday.