Production resumed Tuesday at Freeport McMoRan Copper & Gold’s West Papua mine after a two-week stoppage following one of Indonesia’s worst mining disasters in recent memory, as police and mining ministry officials probed a cave-in that killed 28 and injured 10 others.

“As for operations at the open-pit mine and the mill, we have restarted on May 28 and are slowly ramping up,” said the Indonesian subsidiary of the Phoenix, Arizona-based company, as quoted by Agence France-Presse. Underground maintenance work has also resumed. The evacuation and cleanup took more than a week.

The cause of the collapse remains unclear. An inquiry by Indonesia’s Energy and Mineral Resources Ministry is also ongoing at the collapsed underground training facility, 2.7 km from the Grasberg open-pit mine.

The mine should soon reach a full production rate of 140,000 metric tons per day of ore, said Rozik B. Soetjipto, president director of Freeport Indonesia, according to a Bloomberg News report. During the suspension, stockpiles met existing orders, said company officials.