In a major accident, three contract labourers were killed on the spot when they were trying to remove a coal blockage at the coal mill area of the 500 MW fourth unit of the National Thermal Power Corporation (NTPC), Ramagundam, on Thursday evening.

According to reports reaching here, the contract labourers – S. Venkatratnam (45), N. Sudarshan (40) and Muni (35) -- were working at the bunker maintenance area of the fourth unit of the power station. The workers were trying to remove a blockage at a huge pipe that hindered coal supply when suddenly they were hit by a rush of coal in the wake of air pressure.

They fell from a height of around 20 metres after crashing into a grill meant for the protection of the power station.

Though they succumbed to injuries on the spot, the NTPC authorities claimed that they died while undergoing treatment at the NTPC hospital in the township.

The trade union leaders alleged that the accident occurred due to lack of safety measures for the contract labourers and demanded an ex gratia of Rs.20 lakh to each bereaved family member.

The NTPC authorities have ordered a high level inquiry in the accident.