A portion of a balcony on the second floor of a three-storey building on Deshpran Sashmal Road near Bhavani theatre in Tollygunge collapsed during a spell of heavy rain on Saturday morning.
A 35-year-old pedestrian was injured in the incident.
Chandan Barman from Nandakumar in East Midnapore was rushed to MR Bangur Hospital with a severe head injury.
The incident happened around 7.40am when most shops in the area were yet to open.
Dilapidated and covered with outgrowth, police said 43 Deshpran Sashmal Road had been declared a “dangerous building” by the Calcutta Municipal Corporation.
The ground floor of the building has shops that had not opened when the accident occurred.
“It was quite early and it was raining. We had just opened when the sound of a crash shook all of us,” said an employee of a private health clinic a few steps away.
“The injured man was headed to our clinic with his sister. She had a close shave. One of our staff members accompanied the injured to the hospital.”
Immediately after the collapse, the police cordoned off the area with guardrails and workers were called in to remove the debris.
At the hospital, Barman was taken to the emergency room where doctors said he had suffered a deep gash on his rear head.
“The patient had suffered blood loss and the injury had to be covered up with multiple stitches. Since the patient’s other parameters were fine, we decided not to admit him to the hospital,” said a senior official of the hospital.
Civic engineers said the intermittent rain posed a threat to dilapidated buildings across the city.
There are hundreds of such old and crumbling buildings in Calcutta.
In the past two months, the CMC has pulled down portions of nearly 200 such buildings but many more are still standing in vulnerable conditions.
“We will soon start pulling down a part of the building, which remains most vulnerable before deciding on the entire structure,” said a senior official of the CMC’s building department.