The miners were transported by emergency vehicles to area hospitals Wednesday after they were removed from the Lucky Friday Mine in Mullan, Idaho, The (Spokane, Wash.) Spokesman-Review reported.
The miners were working more than a mile underground in the silver-lead-zinc mine owned by Hecla Mining Co.
The miners were trapped 5,900 feet underground after a rock burst, Hecla spokeswoman Melanie Hennessey said. She said no rock blasting occurred in the 24 hours before the collapse, so the incident was attributed to seismic activity, not the mining operation.
"All employees are out of the mine and have been accounted for," Hennessey said. "Those that were injured are being treated and the mine is currently shut down."
The federal Mine Safety and Health Administration and Hecla are investigating.
The mine is in the midst of a $200 million project to deepen it nearly 9,000 feet to gain access to deeper ore, The Spokesman-Review said. Hecla officials expect the project to be completed by 2014.
Wednesday's accident came about a month after miner Brandon Lloyd Gray was killed after being buried in rubble while trying to dislodge a jammed rock bin. The accident is being investigated by Hecla and Gray's employer, Cementation U.S.A., a contractor hired by Hecla to deepen the mine.