The incident occurred when around 30 persons were working at the site. Two workers died on the spot while another one died when he was being shifted to a hospital, an official attached with Hasanparthy Police said.
Two of the workers killed in the incident were identified as Prasad and Rajesh, he said.
Warangal city police commissioner G Sudheer Babu rushed to the spot and supervised the rescue operation, he said.
A case has been lodged in this regard, the official said, adding that investigations are underway.