KOLKATA: Several people are feared trapped after an under-construction warehouse collapsed in the Taratala area of west Kolkata on Wednesday afternoon, triggering a large-scale rescue operation involving multiple agencies.Police said four people have so far been rescued from the debris.The roof of the under-construction warehouse, located on Transport Depot Road near Brace Bridge in Taratala, collapsed around noon, officials said.A Kolkata Police official said, “The roof of the warehouse located on the Transport Depot Road near Brace Bridge in the Taratala area collapsed around noon. Our officers have reached the spot.“Some people were working at the site at the time of the incident. We fear that quite a few people may be trapped under the debris.”Personnel from Kolkata Police, the Disaster Management Group, civil defence, fire and emergency services, and the National Disaster Response Force (NDRF) were deployed at the site to carry out search and rescue operations.NDRF teams arrived at the spot to assist in the rescue effort as authorities intensified operations to locate those feared trapped under the rubble.Army personnel were also seen assisting in the operation, while cranes and heavy-duty lifting equipment were pressed into service to lift collapsed iron beams, remove debris and clear the site.Visuals from the spot showed cranes being deployed to lift the rubble at the site of the collapse as rescue workers searched through the debris.The state government has opened control rooms at the state secretariat for the incident. The helpline numbers are 1070, 8697981070 and 033-22143526/22535185.