US:Rescue workers have no idea whether six miners are still alive after the collapse of a coal mine in central Utah and it will take at least three days to reach them, a co-owner of the operation said yesterday.
Bob Murray, president and chief executive of Murray Energy, told reporters that there had been no contact with the miners since the disaster early on Monday.
He said that if the miners survived the initial collapse, "there is plenty of air in there for them to survive for weeks and there is water".
Rescue efforts suffered a setback overnight when dangerous conditions, including falling rock, forced teams to retreat.
"It will take three days if everything goes right to get to these miners," Mr Murray said. "At that time, we'll know whether they're alive or dead."
Using heavy equipment to drill from above and teams inside the tunnels, rescuers are trying to reach an area about 450m (1,500ft) underground and 610m (2,000ft) from the closest access point.
"Progress has been too slow," Mr Murray said. "The families are doing fine, considering the circumstances."
Geologists are investigating whether a 3.9-magnitude tremor reported early on Monday morning was an earthquake that might have caused the collapse, or whether the reading resulted from the cave-in.