The National Copper Corporation of Chile, known as Codelco, said a “seismic event” on Thursday afternoon caused the accident. The U.S. Geological Survey recorded a magnitude 5 earthquake 17 miles northeast of Machali, where the El Teniente mine is located, at 5:34 p.m. local time.

Officials say that a worker was killed and five others remain trapped underground after a collapse at a copper mine in Chile

Rescue teams in Chile are searching for five miners trapped after a partial collapse triggered by a tremor killed one colleague and halted operations at the world’s largest underground copper mine.