A seismic tremor triggered a collapse in Chile’s El Teniente copper mine, entombing miners underground and leaving multiple fatalities and ongoing rescue efforts.

At a Glance

• A magnitude‑4.2 seismic event struck near the El Teniente copper mine on July 31, 2025, causing major tunnel collapse.
• One miner, Paulo Marín Tapia, died immediately; four more trapped miners have since been found dead.
• Rescue teams have cleared approximately 24 meters of debris out of an estimated 90‑meter obstacle to reach remaining two miners.
• Around 100 specialized rescuers, including veterans from the 2010 Chile mine rescue, are working on site.
• Authorities have launched a criminal investigation into safety protocols and whether mining activity contributed to the collapse.

Region rocked by major tremor

On Thursday, July 31, a 4.2 magnitude earthquake—among the strongest ever recorded at El Teniente—shook the Andesita section of the massive underground copper mine in central Chile. The quake caused a sudden cave-in that killed one miner and trapped five others approximately 900 meters underground.

Watch now: Chilean Mine Collapses Due to 4.2 Earthquake…5 Trapped · YouTube

Rescue efforts immediately mobilized roughly 100 experts, including personnel experienced in the infamous 2010 Copiapó operation.

Rescue progress and setbacks

Over the weekend, rescue crews made slow but steady progress, clearing 20–24 meters of blocked tunnel at a rate of 15–20 meters per day with heavy machinery and remote-controlled drills.

On Saturday, August 2, rescuers recovered the body of a second trapped miner, raising the death toll from the four remaining trapped workers. By Sunday morning, August 3, three of the five trapped miners had been confirmed dead, bringing the total fatalities—including the initial victim—to five.

Communication with survivors remains impossible due to the ongoing instability and blocked shafts, and officials warn that aftershocks could further delay access to the trapped individuals.

Safety probe and national impact

Codelco, the state‑owned operator of El Teniente—the world’s largest underground copper mine—has formally suspended operations in the affected Andesita area following the incident but continues limited processing in concentrators and smelters using stockpiles.

Chile’s prosecutor has opened a criminal investigation into whether mining operations triggered or worsened the seismic collapse, or if safety protocols failed amid the tremor-prone location on the Ring of Fire.

The site operates beneath Sewell, Machalí (near Rancagua), and has a labyrinth of tunnels over 3,000 km, employing around 5,000 workers annually.

What lies ahead

With approximately 70 meters of tunnel still obstructed between rescue crews and the cavern where two miners may remain alive, the coming hours are widely considered critical. Officials stress that progress must be cautious to avoid triggering further collapses.

Meanwhile, President Gabriel Boric has visited the site, pledging full coordination and expert support while mourning the lives lost. Union leaders warn of mounting pressure on Chile’s mining sector to overhaul underground safety standards after this tragedy—and as national copper production comes under scrutiny.