Exact number of the casualties is not known as rescue operation is in full swing and army has cordoned off the area.
The state government called out the army, which mounted a major rescue operation with teams of doctors and engineers equipped with heavy equipment. Disater management team has also out for rescue.
photo- Anand Bazar Patrika
The army said four columns had been rushed initially to the site, together with a team of army engineers with specialist equipment to remove the large chunks of concrete.
The state government has set up an emergency helpline with number 1070 from the state secretariat Nabanna to provide information related to those injured or killed in the mishap.
West Bengal Chief Minister Mamata Banerjee has cancelled her election campaign rallies after hearing about the tragic incident.