Burdwan, Feb. 23: A day after the collapse of the under-construction flyover on Durgapur Expressway, the National Highway Authority and police launched separate probes to fix responsibility.

The Burdwan police interrogated officials of the Malaysian firm Gamuda-WCT (India), which is executing the contract to develop the expressway, an extension of National Highway 2. The work is part of the Golden Quadrilateral project to develop a nationwide network of highways.

“We are not commenting at this point on which official or agency can be held responsible for the collapse,” said Kailash Chandra Meena, the district superintendent of police.

Gamuda is having the construction — on a 70-km stretch between Palsit in Burdwan and Dankuni in Hooghly — carried out through its Delhi-based sub-contractor, M. Sahay and Company.

The police launched the probe on the basis of an FIR lodged with Jamalpur police station holding the construction company responsible for the collapse.

Among those interrogated were Gamuda’s technical manager M. Subramaniam and P. Dubey, the project manager.

A.R. Ashdam, an engineer from the National Highway Authority of India’s office in Calcutta, visited the site, about 90 km from the city, today and collected samples of materials being used for the construction.

Project director of the highway authority J.K. Goyel, too, visited the spot this morning and spoke to officials of the construction company. “We will examine the materials being used for the construction of the flyover and only after that we will be able to find out the cause of the accident,” he said.

District magistrate Subrata Gupta said the administration had urged the highway authority to conduct a thorough probe into the collapse. “We have also urged them to give us a report of their investigation so that we can initiate action against the agencies engaged in the construction of the flyover,” Gupta said.

The All-Bengal Construction Labourers’ Union, which is controlled by the Citu, demanded adequate compensation for the 16 injured labourers. Pradip Goswami, a Citu member of Bhatar zonal committee, said the union would meet senior officials of the agency carrying out the construction to demand damages.

Goyel said the authority would bear the cost of treatment of the injured. “The condition of two labourers is critical and we are trying to organise adequate medical care. We are also considering proposals to give financial support to the injured. They are not in a position to work now and we are considering giving them financial support till they recover fully,” he added.

Some senior officers engaged in the construction of the flyover suspected that sub-standard materials supplied by a section of the contractors led to the collapse.