New Delhi, Aug. 2 -- A collapse at a copper mine in Chile killed one worker and left five trapped underground, authorities said Friday, forcing Chile's state mining company to suspend operations in affected areas of the world's largest underground copper deposit.

Nine other mine workers suffered injuries, said Chile's National Copper Corp., known as Codelco, describing the incident as the result of "a seismic event."

The U.S. Geological Survey reported a magnitude 5 earthquake in an area of central Chile where Codelco's El Teniente mine is located, at 5:34 p.m. local time on Thursday. Codelco reported the tremor had a magnitude of 4.2.

Authorities said they're still investigating whether it was a naturally occurring earthquake or wheth...