Rescue workers today bored through rock and earth in a frantic attempt to reach nine Pennsylvania coal miners who have been trapped in a flooded mine shaft for over 48 hours.
But with time running out and rescue efforts already delayed 18 hours by a broken drill bit, emergency crews labouring to extend two 30-inch-wide rescue shafts to the stranded men were still at least 100 feet short of their intended target by daybreak.
The first shaft, in which a drill bit broke early Friday morning, had made little progress only several feet of progress overnight with a depth at 110 feet after rescuers stopped the operation again to change drill bits.
But a second rescue shaft had made it to a depth of 140 feet.
"It's still good. We're still progressing," said Betsy Mallison, spokeswoman for the state Department of Environmental Protection, or DEP.
Rescuers continued to have their greatest success at reducing water level in the Que Creek mine, located in rural Somerset County southeast of Pittsburgh.
State mining officials said they needed to lower water level by 30 feet to ensure that rescue drills could break into the compressed air pocket of the underground chamber without causing a change in pressure that would cause water to surge into the rescue shaft.
The miners were excavating bituminous coal 1-1/2 miles from the mine entrance late on Wednesday, when they inadvertently broke through into a flooded adjacent shaft which had been abandoned in the 1950s.