Three workers were killed and one sustained injuries after a hopper filled with coal collapsed on them at an alumina refinery in Chhattisgarh's Surguja district on Sunday, police said.
Rescue efforts are underway to trace one more worker who is missing, they said.
The incident occurred around 11 am at Maa Kudargarhi Alumina Refinery in Silsila village under the Raghunathpur police chowkie, an official said.
As per preliminary information, a steel tower-mounted hopper filled with coal collapsed and fell on men working below it, he said.
The police were alerted, and a team rushed to the spot and launched a rescue operation, he said.
"Bodies of three workers have been retrieved from the site so far, and one worker was found in a critical condition and is hospitalised," the official said.
Another worker is said to be missing, and efforts are underway to trace him, he added.
