Rescuers have been digging day and night while pumping oxygen underground after a tunnel collapsed early this week at Grasberg, one of the world’s largest copper-gold mines in Indonesia, killing four workers and trapping at least 25 others. Energy and Mineral Resources Ministry officials reported some 40 workers were underground when the roof of a training facility caved in. Thirteen miners have so far been extracted safely, according to Dow Jones Newswires. PT Freeport, a unit of Arizona-based Freeport-McMoRan Copper & Gold Inc., temporarily halted underground mining work.


Extraction efforts are labor-intensive, as the access site is small and prohibitive of heavy equipment, thus forcing debris removal by hand, The Associated Press reported. The cause of the cave-in remains unclear but an investigation team was onsite, mining ministry official Thamrin Sihite said.

The dimensions of the affected area are prone to further collapse. “We don’t want to be careless because the terrain surrounding the old tunnel is prone to collapse,” Papua police spokesman Lt. Col. Gede Sumerta Jaya told reporters. A large portion of the training room, 80% which was built in 1998, now lies beneath some 190-cubic-meters of debris while the tunnel itself is 50 m long with five offices, a dining room and three classrooms.

Instructor Kristian Sitepu recalled standing by a 5- x 11-m classroom explaining rescue procedures when rumbling noises presaged rockfalls. He and others in the front row escaped unhurt, while the others were trapped or crushed. “They were shouting for help, but I couldn’t do anything—it hurt me,” Sitepu told The AP.

The rescue work “is difficult and will take some time to complete,” company officials said in a statement quoted by Reuters. “Our thoughts and prayers are with our fellow employees and their families as we proceed with rescue efforts.” Survivors suffered mostly cuts and broken bones.