Three persons were killed and two others grievously injured when a portion of the first floor of a two-storey building collapsed in Kolkata’s Sealdah area on Monday morning. The building located on 15/16 Baithakkhana Road was over 100 years old and occupied by tenants, mostly shopkeepers. At 2 a.m., the roof of the first floor came crashing down, killing Gopal Naskar and Manik Jana, who were sleeping inside the building. Locals said both were shopkeepers. The third victim has not been identified so far. Two others who sustained serious injuries were shifted to N.R.S. Medical College and Hospital. Kolkata Police and Disaster Management Group personnel removed the debris by Monday evening.According to the rescue personnel, overnight rains may have resulted in the collapse of the dilapidated building. Locals also said that the house had been declared dangerous by the Kolkata Municipal Corporation. Normal life was disrupted in several parts of the city on Monday due to heavy overnight rain. Waterlogging was reported in several areas of Kolkata and adjoining districts. In the 24 hours between 5.30 p.m. on Sunday evening and Monday evening, Kolkata recorded 73.8 mm rainfall.Weather officials said depression over Jharkhand and its neighbouring areas was the cause behind the heavy rainfall in Kolkata. “A monsoon trough over some districts of south Bengal will continue to cause light to moderate rainfall before moving north-east towards the Bay of Bengal. Fishermen should not venture out into the seas when the wind speed in coastlines exceeds 45 kmph,” said G.K. Das, director of Regional Meteorological Centre, Kolkata.