After the incident, four rescue teams, using helicopters and heavy equipment, drilled steadily to reach the men, who were stuck some 1,500 feet below the surface in the Crandall Canyon mine. Yet as night fell, the rescue crews had to regroup, hampered by falling rock.
"Every initial effort at rescue has failed," said Robert Murray, president of Murray Energy, which owns the mine operator. "They could be in a chamber that is 1,000 feet long or they could be dead," Murray added. "Time is of the essence.""
There has been no contact with the men since the mine collapsed around 2:50 a.m. Monday.
Rescue crews had come within 1,700 feet of the trapped miners and work was being done to drill from the top and horizontally.
It is not known what caused the collapse, though the U.S. Geological Survey reported a magnitude-4 earthquake near the mine at the time of the cave-in. It is analyzing data to determine whether the shaking was produced by the collapse itself.
"If you have a mine collapse, there will be a seismic component," says Harley Benz of the USGS' National Earthquake Information Center. "We simply don't know at this point."
The area in central Utah, about 140 miles 225 km south of Salt Lake City, is known for its mining industry and has seen its share of tragedy.
"All we can do is wait and pray and let the rescuers do their job and until we hear, we will continue praying with the families of the missing miners," says Brad King, a Utah state representative from nearby Carbon County.
Concerns about mine safety in the United States resurfaced last year when 12 miners were killed in an explosion at International Coal Group's Sago mine in West Virginia.
In response, Congress passed the Mine Improvement and New Emergency Response Act, which President George W. Bush signed into law last year