Outlook Explains | Mumbai's Mankhurd Building Collapse: Why Do Buildings Keep Collapsing Here Every Monsoon?

The rains have taken a deadly turn as six people, including five children, died after a three-storey chawl collapsed in Mumbai's Mankhurd amid heavy monsoon rains this week. The incident occurred in Janata Nagar, Mandala, where the debris from an illegal structure crashed onto adjacent homes.

The tragedy is the latest in a series of monsoon-related building collapses in the Mankhurd-Shivaji Nagar belt, an area long marked by ageing buildings, unauthorised construction and fragile ground conditions. Here's why the locality remains one of Mumbai's most vulnerable during the rainy season.

Why is Mankhurd so vulnerable?

Mankhurd-Shivaji Nagar is densely packed with informal settlements, ageing chawls and unauthorised multi-storey buildings, many located on low-lying, flood-prone land. The combination of ageing structures, poor construction quality and unchecked vertical expansion has made the area particularly susceptible to collapse during the monsoon.

The problem is not new. In 2021 alone, two separate building collapses in Mankhurd claimed 20 lives. Despite repeated tragedies, illegal multi-storey buildings have continued to proliferate, often violating the Brihanmumbai Municipal Corporation's (BMC) 14-foot height limit for informal housing.

According to civic officials, the structure that collapsed this week stood on land owned by the Mumbai Suburban Collector's office, part of a nearly two-square-kilometre stretch that houses more than 1,000 residential units, many of them four storeys or taller.

What makes the soil unsafe?

The Mankhurd-Shivaji Nagar belt lies next to the Deonar landfill, one of India's oldest dumping grounds, operational since 1927. As the city expanded through the 1990s and 2000s, low land prices near the landfill attracted large numbers of low-income migrants.

Much of Mankhurd and neighbouring Govandi was developed on reclaimed marshland and filled-up dumping grounds. Such soil has a low bearing capacity and becomes even weaker when saturated by heavy rainfall, increasing the risk of structural settlement and collapse.

Many houses are also built on brick masonry and temporary materials such as wood instead of engineered foundations. Continuous rainwater seepage weakens mortar, corrodes steel reinforcement and gradually hollows out buildings from within.

Why do illegal buildings continue to exist?

Officials say enforcement has remained stalled because the land falls under the Mumbai Suburban Collector, while demolition powers lie with the BMC. State agencies, meanwhile, lack the manpower to act, leaving the issue caught in years of inter-departmental correspondence.

Another hurdle is rehabilitation. Under a state government resolution, eligible occupants of structures built before 2011 must be rehabilitated before demolition. Officials estimate that over 70 per cent of the housing units in the area predate 2011, making large-scale demolition impossible without a major redevelopment project.

Residents also continue to add extra floors as land becomes scarce. According to local social worker Hasan Shaikh, many single-storey homes have gradually become three- or four-storey buildings, despite repeated demolition drives. Since these structures are inexpensive to rebuild, illegal construction often resumes within days.

Why are these structures hardest hit during monsoon?

Heavy monsoon rain exposes every structural weakness. Water seeps into walls and foundations, weakening already fragile buildings and reducing their ability to bear weight.

The problem is worsened by overcrowding. Civic officials say a single housing unit often shelters around 20 people, placing loads far beyond what many of these structures were designed to support.

In this week's incident, Mumbai Mayor Ritu Tawde said the building that collapsed was illegal, while the family that lost their lives was living in an authorised structure onto which the illegal building fell.

Can authorities prevent future collapses?

Experts and officials say preventing future disasters will require more than emergency action after each monsoon.

The immediate challenge is removing unsafe buildings while simultaneously rehabilitating thousands of residents who depend on them. Authorities will also need stronger enforcement against illegal construction, better coordination between state agencies and the BMC, and long-term redevelopment of vulnerable settlements.

Following the latest collapse, police arrested the owner of the slum pocket and the owner of the illegal four-storey structure on charges including culpable homicide not amounting to murder. Investigators have also booked the contractor involved and unidentified public servants accused of neglecting the illegal construction.

The latest tragedy has once again raised questions over why unsafe buildings continue to mushroom in one of Mumbai's most disaster-prone neighbourhoods despite repeated warnings and past collapses.