Experts say heavy rain and strong winds are usually the final trigger, while years of root damage, concretisation, poor pruning, fungal decay and ageing weaken trees over time.
Arborists say hazardous trees can often be identified in advance using internationally accepted tree-risk assessment methods and diagnostic tools, but Mumbai largely relies on visual inspections and reactive maintenance.
Protecting tree roots during infrastructure projects, reducing concretisation around trunks, maintaining a digital tree inventory and adopting year-round scientific monitoring could significantly reduce tree collapses before future monsoons.
Every monsoon, Mumbai's trees become both a symbol of the city's green cover and a growing public safety hazard. Heavy rains and gusty winds routinely bring down hundreds of trees and branches, blocking roads, disrupting power supply, damaging vehicles and, increasingly, costing lives.
But experts say rainfall alone is rarely the reason. Most tree failures are the result of multiple stressors that have accumulated over years damaged roots during infrastructure projects, concretised tree bases, poor pruning practices, fungal decay, ageing, and inadequate scientific monitoring.
The BMC says tree failures cannot be blamed solely on concretisation, urban ecologists argue that many collapses are preventable if trees are regularly assessed using internationally accepted risk-assessment methods rather than reactive inspections. The debate raises a larger question: why do Mumbai's trees continue to fail every monsoon, and what would it take to prevent the next tragedy?
Why are so many trees falling in Mumbai?
Tree falls are not unusual during the monsoon. Saturated soil reduces root stability, while strong winds place enormous pressure on large canopies. However, healthy trees with intact root systems generally withstand such weather.
What makes Mumbai particularly vulnerable is the cumulative impact of urbanisation.
According to BMC data cited by The Indian Express, the city recorded 687 tree-fall incidents in 2023, 653 in 2024 and 855 in 2025, showing that hundreds of trees collapse every year.
Urban trees in Mumbai often face multiple stresses throughout their lives. Excavation for roads, Metro projects, utility lines and drainage works frequently cuts or damages roots. Tree pits are often covered with concrete, limiting water infiltration, oxygen exchange and root expansion. Poor or excessive pruning can also leave trees structurally unstable.
What caused the latest spike in tree collapses?
The 2026 monsoon has witnessed one of the sharpest increases in tree-fall incidents in recent years.
According to BMC figures reported by The Times of India, 826 trees fell within the first 14 days of the monsoon—an average of 59 every day or more than two every hour.
Several high-profile incidents have renewed attention on tree safety.
In Chembur, an 11-year-old boy died after a roadside tree fell on a school bus. A preliminary BMC inquiry found that the tree suffered from extensive internal decay and damaged roadside roots, significantly weakening its structural stability.
Separate media reports also revealed that civic officials had previously flagged root damage near the site caused during road works months before the fatal collapse, raising questions about whether preventive intervention could have avoided the tragedy.
Can dangerous trees be identified in advance?
Yes, but doing so requires scientific assessment rather than visual inspection alone.
Modern arboriculture relies on Tree Risk Assessment methods developed by organisations such as the International Society of Arboriculture. Arborists examine visible defects, root condition, trunk decay, canopy health, soil conditions and surrounding land use to estimate both the likelihood of failure and the potential consequences.
Where internal decay is suspected, specialists use advanced diagnostic tools to confirm the damage and take appropriate action.
Such assessments allow authorities to prioritise trees needing pruning, support systems or removal before they become dangerous.
However, these methods require trained arborists, specialised equipment and regular monitoring.
Why doesn't the BMC use scientific tree-risk assessment?
The BMC does conduct inspections and pre-monsoon pruning, but critics argue that the system remains largely reactive or inadequate. Tens of thousands of trees in Mumbai require annual pruning before the monsoon.
A report by The Indian Express states that the budget for the tree and garden department was reduced from ₹220 crore to ₹200 crore. The funds which are available are mostly used maintenance of parks and gardens.
Environmental groups have long argued that inspections rely too heavily on visual observations rather than internationally recognised risk-assessment techniques.
A comprehensive risk-based inventory—where every tree is periodically assessed, assigned a risk score and monitored digitally—would allow civic authorities to identify hazardous trees before failure rather than after accidents occur.
How do concretisation and infrastructure work weaken trees?
Perhaps the most contentious issue is road concretisation.
Mumbai is currently undertaking one of its largest infrastructure projects, replacing asphalt roads with concrete. Environmentalists argue that many roads have been concretised right up to tree trunks, reducing exposed soil around their bases.
Trees depend on their roots not only for anchorage but also for oxygen, water and nutrient absorption.
Concretisation hinders a tree’s basic processes while also damaging its structural integrity reducing a tree’s stability over time.
The BMC argues that while concretisation may contribute in some cases, factors such as ageing, fungal infections, pests, previous storm damage and improper pruning are also significant contributors.
What needs to change before the next monsoon?
Preventing future tree collapses requires shifting from emergency response to preventive management.
Scientific tree-risk assessment policies as well as protecting trees during concretization drives are key steps that must be undertaken.
Climate change is also likely to increase the frequency of intense rainfall and extreme wind events, making resilient urban tree management even more important.
Trees remain essential to Mumbai's environmental health, providing shade, reducing urban heat, absorbing carbon and managing stormwater. The challenge is ensuring that these benefits do not come at the cost of public safety. As recent fatalities have shown, preventing the next tree collapse is less about responding after storms—and more about managing trees scientifically throughout the year.
