Two labourers who were cleaning a septic tank at a restaurant in AECS layout in Bengaluru died of asphyxiation on Tuesday, ANI reported. The Bengaluru Police have booked the restaurant owner, manager and caretaker.

The restaurant’s management had asked Ramu and Ravi to clean the septic tank around 4 pm on Tuesday. Ramu entered the tank using a rope while Ravi stood outside to collect the waste, The Hindu reported. Venkatesh, the restaurant’s caretaker, stood outside to oversee the cleaning.

“Within minutes, Ramu collapsed inside the tank,” an unidentified senior police officer said. “When Ravi did not hear anything from Ramu despite his repeated calls, he too entered the tank. Both of them died in the tank.” The officer added that the management had neither provided the workers any safety gear nor trained them in cleaning work.”

Fire and emergency services arrived at the scene after Ayush Gupta, the restaurant’s manager, informed them of the incident. The two workers were rushed to a hospital in Whitefield but were declared brought dead.

The police arrested Venkatesh and Ayush Gupta. They also detained the restaurant’s owner, Avinash Gupta. “We arrested two persons and have taken up a case of culpable homicide not amounting to murder against them,” a police officer said. He said that the provisions of a 2013 law barring employment as manual scavengers were also slapped against the accused.

Bengaluru Deputy Commissioner of Police Abdul Ahat said the police had called Bruhat Bengaluru Mahanagara Palike Health Inspector Devraj for questioning, because the restaurant was built in the basement. The municipal corporation’s Joint Commissioner (Health) Sarfaraz Khan said the civic body had rejected the restaurant’s application and it was operating illegally.