Three workers in a gold workshop in the city were asphyxiated to death while cleaning a tank full of chemical and other waste. The mishap occurred in the wee hours of Friday.

According to police, workshop owner Ravishankar had asked two workers – Ezhumalai and Gourishankar – to clean the tank in RS Puram around 3 am. Hearing the screams of the two who were found struggling to breathe, supervisor Suryakumar rushed to the spot and made a bid to rescue them. However, he also fell unconscious due to foul odour from the tank, police said.

Both the workers died on the spot, while Suryakumar died on admission to the Government Hospital.

Police have registered a case under 304 A (causing death due to negligence) against Ravishankar, who is said to be absconding. Relatives of the deceased, who gathered in the hospital, demanded immediate action against Ravishankar, as the workers were inexperienced in cleaning such tanks and undertook the work without protective guards.