Freeport-McMoRan Copper & Gold Inc. announced its Freeport Indonesia subsidiary has partly resumed open-pit operations at its Grasberg site following Mining Ministry approval in wake of a deadly cave-in last month. Open pit and mill work are resuming incrementally, according to Freeport officials. Underground operations will increase pending further permission by Indonesian regulators.

On May 14, a training tunnel collapse killed 28 workers and injured 11 others in one of the worst mining accidents in recent Indonesian history. An unrelated death just days later prompted authorities to shutter all operations ahead of a full nationwide review of underground mining operations by Jakarta authorities.

Freeport Chairman James R. Moffett and CEO Richard C. Adkerson issued a joint statement expressing “deepest condolences” to the families of the deceased and injured workers with “appreciation to Indonesia for its thorough review…This was an unprecedented event in our more than 40-year history of operations in Papua and we are taking all actions to prevent future incidents.”

The closure led the Phoenix-based Freeport to declare force majeure, which has yet to be lifted. According to analysts, its impact on Freeport production stands at 115 million copper lb and more than 110,000 gold oz.