The rescue operation, conducted by the disaster management department and fire brigade in cooperation with the police and local administration, was completed in about four hours.
Fire Brigade sources said they rescued the trapped residents of the building at 10 Sitanath Bose Lane with the help of ladders of three fire tenders which were deployed soon after the incident.
Since the building was very old and two of those trapped were aged and sick, it was very tough to conduct the rescue operation, sources said.
All these residents were trapped after the debris from the collapsed-roof blocked the stairs.
There was no casualty or injury, sources said.