According to Fire Department, they got a call about the incident at 11:55 am following which five fire tenders were rushed to the spot. Fire fighters and police personnel soon launched the rescue efforts.
"The basement being built is around 40 feet deep. A makeshift wall was erected to keep the mud from collapsing, but that wall cracked and the debris fell on the four workers who were working on the spot," said Deputy Commissioner of Police (South-West) R A Sanjeev.
The deceased were identified as Santosh (25), Jittendra (26) and Gulzar (21). Their colleague Ali Hasan was injured in the mishap.
Police said that the hospital administration had taken all sorts of permission for the building but proper safety norms were not followed by the construction company. An FIR has been registered in this regard against the company.
"We have registered a case against the construction company for causing death due to negligence (304 A) and Negligent conduct with respect to pulling down or repairing buildings (288) under IPC. Further investigations are on," the official added.