The overnight search and rescue operations at the Majerhat bridge collapse site in the south Kolkata continued Wednesday morning to find those possibly trapped in the debris, officials said.

A section of the over 50-year-old bridge on the arterial Diamond Harbour Road in south Kolkata collapsed Tuesday evening, killing one person, trapping several people and crushing many vehicles.

Amid rains, the rescuers tried drilling the concrete slabs, used sophisticated cameras and engaged sniffer dogs to ensure anybody trapped under the rubble could be reached and rescued. Additional lighting arrangements were made to aid the rescue works at night, the officials said.

"There could be a few trapped underneath the collapsed bridge. We are trying to find them out. We are using cutters and drill machines to cut through the concrete slabs of the bridge. Till now, we are unable to locate anybody. We are trying our best," an official of the rescue team said this morning.

The area near the site had been dug up for a metro railway project and construction material are strewn all over the place. Labourers working on the metro project claimed that two of their co-workers, who were probably inside a temporary shelter underneath the bridge, were missing.

The Kolkata Disaster Management Department, the Disaster Response Force (NDRF) and the state fire department conducted the search operations throughout the night, the officials said.

The police had said Tuesday evening that 27-year-old Soumendu Bag had died in the collapse while 21 others, including three women, were injured. The injured are receiving treatment at the hospitals in the city.

A mini bus, four cars and a few motorcycles that were damaged in the bridge collapse were removed using cranes, the official said.

Meanwhile, traffic has been diverted to other routes. The Majherhat bridge connects extended areas of South 24 Parganas district with the city.

An official of the Kolkata Traffic Police said, "We expect traffic jam because the Majherhat bridge has collapsed. It is the main link between Behala and the further south areas of South 24 Parganas district. To avoid traffic congestion, Behala-bound buses and other vehicles availing Diamond Harbour Road from Hastings crossing will be diverted via Khidderpore crossing CGR Road, Hide Road, Brace Bridge, Taratala Road Taratala crossing further South."



Tram services have been completely suspended along CGR Road-DH Road and Judges Court Road, he said.

Meanwhile, early Wednesday morning, BJP MP Roopa Ganguly paid a visit to the site. She held the state government responsible for the mishap alleging that the bridge was not maintained properly.

Chief Minister Mamata Banerjee, who is now in Darjeeling, is expected to return the city today and visit the site.

The Majerhat bridge in the crowded Alipore area had caved in around 4.45 pm on Tuesday. Banerjee has said that a probe would be conducted by a committee headed by Chief Secretary Malay De to find out the cause of the collapse.

This is a third bridge collapse in the city in five-and-a-half years.

An under-construction flyover had collapsed in crowded Burrabazar area, the wholesale business hub of the city, on March 31, 2016 that had claimed 26 lives.

On March 4, 2013, a road bridge had collapsed in Ultadanga area in the northern part of the city but there was no casualty.