The government has decided to seek an explanation from Ircon that constructed the Bagha Jatin overbridge, parts of which collapsed on August 18.

Urban development minister Asok Bhattacharya said on Thursday that his department has summoned Ircon officials.

A preliminary report by Jadavpur University’s department of construction engineering, which probed the collapse, has expressed doubts about the quality of workmanship and concrete work, arrangement of steel reinforcements and the thickness of the slabs.

The report has been submitted to the CMDA, which had funded the three-lane bridge that was opened to traffic in 2001.

“We have written to the railway authorities, but they haven’t yet responded. We will now write to Ircon. The CMDA had shelled out Rs 16 crore for the bridge,” the minister said.

The bridge, over the railway tracks, connects EM Bypass to Garia.

The railway authorities have refused to take any responsibility for the collapse or repairs. Swapan Mondal, the divisional railway manager (Sealdah). said: “It is not our duty to carry out repairs. The bridge was built by the CMDA, which is responsible for the upkeep.”

D.D. Bhattacharya, the chief engineer (traffic and transport) of CMDA, said the railway authorities are responsible for the maintenance of the bridge, as it has come up over the tracks.

“However, we have got only a preliminary report. The picture will be clear after the final report is received,” he said.