A portion of a tunnel under construction between Silkyara and Dandalgaon on the Brahmakhal-Yamunotri national highway here collapsed on Sunday morning, trapping 36 workers inside, officials said.
Police, National Disaster Response Force and State Disaster Response Force personnel are at the spot carrying out rescue efforts, Uttarkashi Superintendent of Police (SP) Arpan Yaduvanshi said.
He added that the incident occurred between 6 am and 7 am.
As per records made available by officials of the National Highways and Infrastructure Development Corporation Limited (NHIDCL), 36 labourers are trapped inside, he said.
