The victims, who were trapped inside the plant, died trying putting out the fire, said officials.
Sundar Nayak and Pawan Kumar, engineers at the Srisailam hydro-electric power plant in Telagana, had recently won their battle against COVID-19, but on Friday, Mr Nayak was not so lucky to survive a fire at the unit that left another eight dead.
The major fire at the power plant located on the Telangana side of the border with Andhra Pradesh had left nine people dead, most of them engineers, and three seriously injured.
Mr Kumar, Divisional Engineer, and Assistant Engineer Nayak had been recently cured of the deadly virus.
Incidentally, Mr Kumar resumed work on Thursday, when the fire broke out at the plant, after he went on ten days' leave to attend to his mother who also tested positive for coronavirus, D Prabhakar Rao, Chief Engineer of Srisailam Left Bank Hydroelectric Power Station (SLBHES), said.
"Pawan Kumar tested positive last month, but he recovered and joined duty about 15 days ago. However, he again went on leave as his mother also tested positive recently. He joined duty on the same day the fire incident took place," Mr Rao told PTI.
"Sundar Nayak (AE) tested positive last month and he joined duty more than 20 days ago," he added.
Mr Nayak belonged to Jigani Thanda of Chivvemla Mandal of Suryapet District.
Mr Kumar escaped the fire on Thursday itself.
In the tragic incident, all nine people appeared to have died due to asphyxiation though there were minor burns on their bodies.
A woman was among the dead and thick smoke had hampered rescue operations for over 12 hours after the fire in the electric panels of the underground powerhouse.
The victims, who were trapped inside the plant, died trying putting out the fire, officials had said.
The CID has launched a probe into the matter.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)