On Tuesday, Sonibai Bhawan at Kalwa collapsed, killing 10 and injuring five residents. The unauthorised building was constructed in 1980-81.
On August 3, Babu Hafiz Zindani Apartments near Kalwa naka collapsed after it began sinking. This illegal building was constructed in 1982
On June 20, Vilas Apartments near Manishanagar, Kalwa, began tilting and developed cracks. This three-storey unauthorised building was built between 1980 and 1986.
These buildings were not even on the list of 55 structures listed as illegal in Kalwa. Though the Thane Municipal Corporation (TMC) had information about them, no action was taken till they collapsed. It was only after the Sonibai Bhawan collapse that the TMC hurried to draw up a cluster development plan as a precaution against such incidents.
Defending their inaction, civic officials said nearly 90 per cent of the buildings in Kalwa are illegal and it is not possible to take action against all of them. The only solution, they said, is cluster development — the demolition of all buildings in an area and a planned township being built in their place. The TMC will send its proposal to the state government soon.
"These buildings did not come up in a day, but over several years. There are several such buildings in Kalwa, Mumbra and Wagle Estate. These buildings are unsafe; they don't have much space between them to allow emergency services such as the fire brigade or ambulances," said Thane Municipal Commissioner R.A. Rajeev.
The TMC has now written to the Mumbai Transformation Support Unit (MTSU) to survey the area for cluster development.
"We will have to tell the government how much floor space index is needed and find a viable development model," said Rajeev.
Despite Tuesday's collapse, the TMC has not evacuated residents of 26 very dangerous buildings, including three in Kalwa. There are 805 dangerous buildings within TMC limits.
"We have served them evacuation notices, but, on humanitarian grounds, we cannot force them to leave," said Deputy Municipal Commissioner (Anti-Encroachment) B.G. Pawar.