At least 17 workers were killed and many others are feared trapped after a construction platform at an under-construction railway bridge collapsed near the Sairang area of Mizoram on Wednesday, Chief Minister Zoramthanga said.

There were 40 workers at the site when the accident took place around 10 am. A rescue operation is underway by state authorities.

An Aizwal district official told Scroll that the deceased were migrant workers engaged in the construction work by the Railways.

The Railways said that the tragedy occurred due to the collapse of a gantry that was being launched on the bridge over the Kurung River. Gantries are heavy steel structures used to lift and support bridge segments or girders as they are placed while being supported by the bridge piers instead of the ground, according to PTI.

“The bridge did not collapse,” a spokesperson for the Railways said. “It was a gantry which fell while it was being launched on the under-construction bridge.”

Railway Minister Ashwini Vaishnaw announced an ex-gratia payment of Rs 10 lakh for the families of the deceased. He also said that a compensation of Rs 2 lakh will be given to those seriously injured and Rs 50,000 to those who suffered minor injuries.

Zoramthanga said that he was saddened by the tragedy. “I extend my deepest condolences to all the bereaved families and wishing a speedy recovery to the injured,” he tweeted. “Sending gratitude to the people who have come out in large numbers to help with rescue operations.”

Prime Minister Narendra Modi announced an ex-gratia payment of Rs 2 lakh from the Prime Minister’s National Relief Fund to the families of the deceased workers, while Rs 50,000 will be given to the injured.

Congress President Mallikarjun Kharge offered his condolences to the families of the deceased.

“Our heartfelt sympathies and thoughts are with the families of the bereaved,” he said in a tweet. “We hope for the speedy recovery of the injured. We urge the authorities to expedite the rescue and relief work, so that precious lives can be saved.”

West Bengal Chief Minister Mamata Banerjee said that some of the deceased workers belonged to the state’s Malda district.

“Have instructed my chief secretary to coordinate with Mizoram administration at once for rescue/ assistance operations,” the Trinamool Congress chief said in a tweet. “Malda district administration has been asked to reach out to the bereaved families for extending all possible help.”

She added that the state government will also provide compensation to the families of the deceased.