The two workers electrocuted at Alipore zoo on Thursday might have come in contact with an underground cable, CESC sources said.

A team from the power utility visited the site, near the elephant enclosure, on Friday. “A portion of the ground was dug up. Prima facie, it seems the workers had come in contact with an underground wire that was damaged while digging the ground,” a CESC official said.

“The hole was filled with water because of rain and the team could not access the wire. The team is likely to visit again on Saturday.”

Two contractual labourers were electrocuted and a third was injured after 1pm on Thursday, a zoo official said. Metro erroneously reported that the accident had occurred around 11.30am.

The injured person, Liton Das, was brought out of ventilation on Friday. Tarani Ghosh and Pradip Das had been declared dead on arrival at a private hospital.

A contractual labourer who was part of the group said on Friday that Ghosh had come in contact with the wire first. Pradip Das had tried to save him and Liton Das had tried to save Pradip Das.

The Bengal Zoo Authority has ordered a probe. A team comprising electrical engineers was to have visited the spot. “They could not come today because of the lockdown. They will come tomorrow,” said Asis Kumar Samanta, the zoo director.

Police have registered a case of unnatural death. “The post-morten report is awaited. There is no complaint of negligence till now,” said an officer.

Calcutta High Court advocate Jayanta Narayan Chatterjee said the absence of a complaint did not prevent the police from registering a case suo motu.

“Two people have lost their lives. The police cannot wait for the zoo to conduct a probe. They should have registered a case of death due to negligence and started a probe to ascertain what happened,” he said.