Falling rock and the ongoing threat of more rock falls have forced rescuers to give up on the direct route to 53-year-old Larry Marek, who has been trapped in an Idaho silver mine since Friday.
Rescuers had been trying to dig through the rubble that fills a mine tunnel more than a mile underground. But a relatively small, remotely-controlled mucking machine was only able to make 40 feet of progress in three days.
After that effort, rescuers were about 50 feet away from the area where Marek is believed to be trapped. But the volume of rock blocking the tunnel and the threat of more cave-ins forced them to abandon that effort.
"Rescue operations have been suspended" from that direction "due to worsening ground conditions," says Amy Louviere, a spokeswoman for the federal Mine Safety and Health Administration (MSHA), which is supervising the rescue effort.
Instead, rescuers are using explosives to blast through rock from a different tunnel and direction underground. That route is about 225 feet, Louviere says. "This will be a slow process," she cautions.
As rock is blasted and removed, timbers are used to brace the roof and prevent further rock fall.
Crews are also drilling a two-inch hole into the caved-in area in an effort to establish communication with Marek. It's not known whether he survived the collapse at Hecla Mining Company's Lucky Friday mine in Mullan, Idaho.
That hole is more than halfway through 150 feet of rock that separates the drillers from the area they're trying to reach.
Marek's precise location is unknown. But rescuers believe they know where he is likely to be because he was working with his brother, who managed to escape, when the mine roof collapsed.
The Lucky Friday mine has compiled an injury rate that was worse than the national average in eight of the last 11 years, according to MSHA records. [Click on the title "MSHA Mine Overvew" in the box below to see data on the injury rates and citations at the Lucky Friday mine.]
Hecla Mining Company has posted sketches of the mine, which show the area affected by the rock fall. Hecla also posts updates on its website but these do not seem to be keeping up with developments reported by MSHA.
MSHA is not posting any information about the rescue effort on its website. Instead, the mine safety agency notifies reporters when new information is available.
Update at 3:15 p.m. ET. An Update From The Company:
Hecla Mining's latest statement about the cave-in and the rescue effort is now posted here. It says, among other things, that:
"The Company is working extraordinarily hard to reach Larry and will continue making every effort as long as it takes, using safe methods in the process in order to avoid risk to the rescue teams.
"Rescue crews are working 24 hours a day in two 12-hour shifts."
Update at 6:00 p.m. ET: Former MSHA official Celeste Monforton is familiar with the Lucky Friday mine and she has this post on her blog about the mine's safety record.
[Howard Berkes covers rural affairs for NPR and has been reporting about "Mine Safety in America."]