The two units of 110 mw each were shut down following the mishap. Vital equipment of units 5 and 6 of `B' station including unit control and panel boards, switch gears, gate wall distribution control panels and opening and closing panels were reduced to ashes.

Officials of the AP State Electricity Board (APSEB) are yet to assess the cause of the accident. According to board sources, the fifth unit of the B station tripped at 9.30 pm when some employees saw smoke coming from a turbine floor. By the time fire tenders reached the place, the sixth unit too tripped and caught fire. With fire and smoke engulfing the area, power generation as well as supply was stopped.

The fire was extinguished at 10.30 am today after 17 fire tenders battled for 12 hours. However, no one was hurt.

Chief Minister N Chandrababu Naidu who reviewed the situation has asked the officials to take steps to restore normal generation. Speaking to mediapersons, the Chief Minister said that the officials were assessing the total damage to the thermal station. According to current indications, it may take at least a month for the two units to be restored.

The KTPS mishap occurred within two months after the seven units of the hydel power station at Srisailam were damaged by flood water, causing huge loss. Only three units at Srisailam could be recommissioned so far.

APSEB chairman J Parthasarathy, who rushed to KTPS, said that the B station was set up in 1977 at a cost of Rs 52 crore. The station was handed over to the BHEL for remodelling

He said that a special team from Hyderabad would visit the plant to assess the damage. ``It is difficult to quantify the loss unless the team assesses the damage,'' he added.

Director General of Fire Services Swaranjit Sen said that heavy smoke billowed from the cables, forcing workers and technicians to abandon the area. The local fire vehicle from Kothagudem and KTPS plant were pressed into service immediately.

Subsequently, 17 fire tenders and other equipment were rushed to the spot from Khammam and neighbouring districts like Nalgonda and Warangal, he said.