A platform shed under construction at Shalimar station in Howrah collapsed on Monday afternoon, killing a labourer and injuring at least another.

No passengers were harmed, railway officials said.

The 70ft-long and 50ft-wide concrete structure that collapsed on Monday had been cast in May, an official of the Railway Protection Force said. Its scaffolding was being removed when the structure came crashing.

“The shed at the rear end of platforms 2 and 3, where there is no passenger movement, came crashing down around 2.55pm,” a railway official said.

A few labourers were trapped under the debris for over 30 minutes before help arrived, some residents and passengers alleged.

But railway officials said only two persons were admitted to hospital.

The dead labourer has been identified by the railways as Dukha Chaupal. A portion of an electric pole fell on him, witnesses said. The injured, Alamgir Mallik, is undergoing treatment at Howrah State General Hospital.

An official of South Eastern Railway, under which Shalimar station falls, said the yard master and some railway employees had rushed to the spot immediately after the crash. “But some residents beat up the yard master,” he said. Yard master Dulal Biswas was admitted to hospital with head injuries, he said.

“The general manager, Sanjay Kumar Mohanty, has formed a high-level committee to probe the incident. The reason of the crash will be clear after the panel submits its report,” said Sanjoy Ghosh, the spokesperson for South Eastern Railway.

The shade had been built under an upgrade plan for the station sanctioned by Mamata Banerjee, the then railway minister, in 2010-11. The contract had been awarded to IRCON International Ltd, a central government undertaking incorporated by the railway ministry.

A team from the National Disaster Response Force visited the site in the evening.