HUNTINGTON, Emery County — Rescuers suffered a heartbreaking setback today in their attempts to reach six miners trapped 1,500 underground in a collapsed mine shaft.

The Crandall Canyon Mine's owner said seismic activity in the mine has made it nearly impossible for rescuers to proceed. It could now be at least a week before rescuers are able to reach the trapped miners.

"We're back to square one," said Bob Murray, the president of Murray Energy Corp., which owns the mine.

In a "good news, bad news" conference, Murray told reporters gathered outside the mine this evening that rescuers will have to wait for the seismic activity to stop before proceeding underground. By Wednesday afternoon, miners hope to begin stabilizing the mine shafts with timber and chainlink to protect against more cave-ins.

Meanwhile, they will push forward with attempts to reach the trapped miners through drilling efforts outside the mine. Murray said those drilling operations are underway tonight. One will put a 8 5/8-inch hole 1,500 feet down to the miners and may be able to reach them in 2 days.

"Down that borehole we can provide communication wires, we can provide cameras, we can provide light, we can provide ventilation, we can provide sustenance for the miners," he said. "Anything that they need."

It could be another 48 to 72 hours before mine officials know the status of the trapped men. Murray said they do not know if the men are alive or dead. "If the miners were killed at the time of the earthquake, that's in the Lord's hands and what's done is done," he said.

The seismic activity has been problematic for rescuers since the mine originally collapsed early Monday morning.

"There has been seismic activity," said assistant Labor Secretary Richard Stickler. "Bumps, movements of the mountain. This puts a safety hazard to the rescue workers."

Miners on their way out of the canyon were instructed not to speak with reporters as they piled out of black transport trucks. Two miners with blackened faces were silent as they climbed into their car and drove off. One man in a camouflage hat would only say that he was "tired" after working all night.

Rumbling about earthquakes

During the news conference, Murray angrily insisted that the mine collapse was caused by an earthquake in the area, not a seismic event inside the mine. Scientists at the University of Utah Seismograph Stations have suggested the collapse of the mine registered 3.9 on the Richter scale.

"This was caused by an earthquake," Murray told reporters. "It was a natural disaster."