Work crews trying to reach nine Pennsylvania coal miners trapped in a flooded mine shaft scrambled to resume rescue drilling operations today after their drill bit broke while still at least 45 metres from the men, officials said.
It was a dramatic setback for rescue efforts aimed at saving the miners from a growing threat of hypothermia more than 30 hours after a cave-in left them stranded in dark, wet conditions as cold as 50 degrees Fahrenheit (11 degrees Celsius).
A giant drill rig on which the main rescue plans hinge suspended operations early this morning after its 76-cm wide bit broke on rock or coal about 30 metres below the surface at the Que Creek mine in Somerset County, 95 km southeast of Pittsburgh.
State officials used a helicopter to fly in a piece of equipment to retrieve the broken piece of machinery from the intended rescue shaft. But four hours later, work crews were still trying to retrieve the bit and replace it with a new one.
"It's fifty-fifty, the likelihood of success," said Pennsylvania Gov Mr Mark Schweiker. "It puts you in a very prayerful mood."
Meanwhile, work crews were also preparing to dig a second rescue shaft 23 metres from the initial drill site. Before the breakdown, state officials had hoped to reach the underground mine cavity before dawn, setting the stage for a possible rescue operation using special baskets that could be sent into the newly drilled shaft.
But this morning, the best news rescuers could offer was that a series of makeshift pumping stations had managed to reverse the tide of rising ground water at the Que Creek mine.
Rescuers began pumping compressed air into the mine shaft 90 metres below the surface five hours after the miners accidentally drilled into an abandoned flooded mine, releasing millions of litres of water into their own shaft and triggering a cave-in.
State and federal mine authorities believe the air line created an air pocket for the trapped miners, aged 25 to 50.