Two contract workers were injured after a portion of the roof of the Kondapur underground coal mine fell on them in Manuguru mandal on Friday.
The incident occurred when a total of four workers, including two Singareni Collieries Company Limited (SCCL) regular employees and two contract workers, were carrying out roof bolting work to strengthen the roof support system in the underground mine at about 11 a.m. on Friday.
A roof rock suddenly collapsed on two contract workers injuring them grievously, sources said.
One of them suffered multiple fractures and other external injuries.
Both the SCCL employees narrowly escaped unhurt.
The two injured contract workers from Madhya Pradesh were shifted to the Singareni main hospital in Kothagudem.