NEW DELHI, India (AFP) — Nine workers were killed at a waste-to-energy plant in western India after a garbage heap collapsed onto an administrative building following heavy rains, the facility’s operator said Monday.

The accident occurred last Wednesday at the Antony Waste plant on the outskirts of Pune, when thousands of tons of waste from a nearby landfill gave way, trapping 23 people inside the building.

“The incident, triggered by incessant rains causing thousands of tons of waste from an adjacent landfill to destabilize, severely damaged the structure where 23 personnel were present,” the company said in a statement.

Nine were killed and the other 14 were rescued alive.

Rescue efforts were hampered by the rain as workers struggled to reach those buried under debris, according to plant officials.

Operations at the plant have been temporarily suspended pending structural and safety assessments.

Building and construction accidents are common during India’s June-to-September monsoon season, with old and rickety structures buckling after prolonged downpours.