Two workers from a private company died of asphyxiation while working in a tank in Anna University campus in Chennai on Tuesday.

According to the Times of India, the two workers, Deepan (35) and A Ramesh (45) from Ayapakkam, had climbed into a sump tank to paint it on Tuesday afternoon. Their absence was not noticed till family members complained that they had not returned home from work on Tuesday. They were finally found dead in the tank on Wednesday.

However, The New Indian Express states that the workers went into an ‘air tank’, which was part of a project to conserve wind power. Director of the Institute of Energy Studies and principal investigator of this project, R Vel Raj told TNIE, “Since we are going to store compressed with air, the wall must be lined with rubber. This work was assigned to a company called Kavi Meena which is licensed to do rubber lining,” he said.

He also added that the university authorities do not know what exactly had happened but they think that the two workers may have been affected by the adhesives employed. University sources said that the workers were working without supervision.

The relatives also alleged that they were not even informed about the death of the workers. The bodies were moved to the Government Royapettah Hospital for post-mortem.