Crews working around the clock to reach 53-year-old Larry Marek have so far dug through 37 feet of earth in the Lucky Friday Mine, Hecla Mining Company spokeswoman Melanie Hennessey said early Monday.
The roof of the tunnel more than a mile underground collapsed Friday, trapping Marek. Officials have not had contact with him and don't know his condition. He is a 30-year mining veteran, 12 of those years have been with Hecla.
Later Monday, the digging machine - a front-end loader modified for mining and called a mucker - will go into operation allowing them to work faster and more safely.
"The remote-control mucker has been sent underground and is being reassembled. It is expected to be operational during the day," the company said.
The machine will move material "without needing all the additional ground support to ensure the safety of our rescue teams," the company said.
"In the meantime, rescue crews continue to safely advance and progress on the removal of material," the company said.
Marek and another worker had just finished watering down blasted-out rock and ore when the collapse occurred about 75 feet from the end of the 6,150-foot deep tunnel, according to the company. Marek became trapped but his companion escaped. Family and media reports have identified the other worker as Marek's brother.
The cave-in area is 75 feet in length and 20 feet wide. Officials say it's unclear if the entire 75-foot section collapsed, or only a portion of it, possibly leaving the miner trapped on the other side. As of early Monday, rescuers had tunneled the 37 feet.
The mine is tucked into the forested mountains of Mullan, a historic mining town of 840 people in Idaho's Panhandle.
The company said all mining activity has been halted for the rescue effort. Officials said they will focus on how the collapse occurred once the rescue is complete.
The mine employs roughly 275 workers, about 50 of whom were underground in various parts of the mine when the collapse occurred, company spokeswoman Melanie Hennessey said.
On its website, Hecla describes itself as the oldest U.S.-based precious metals mining company in North America and the largest silver producer in the U.S. It is headquartered in Coeur d'Alene, Idaho. Hecla currently produces silver from two mines, Greens Creek and Lucky Friday, a mine that has been operational since 1942 and is one of the nation's deepest underground mines.
The company appears to have a good record of health and safety at Lucky Friday. There have been no fatalities dating back to 2000, according to a Mine Safety and Health Administration database. The federal regulator has cited the mine for violations, but none in the last year specifically tied to the kind of accident that occurred Friday.
In 2009, the company agreed to pay $177,500 in fines for violating federal clean water laws at Lucky Friday. EPA investigators said the mine exceeded discharge levels for metals such as lead, zinc, cadmium and suspended solids between September 2008 and February 2009. Discharges flow into the South Fork Coeur d'Alene River above the town of Mullan.