Extreme rainfall event in the Darjeeling district: 04/05Oct2025 (Part IIIA - 'Overall damage and fatal landslides')

 BEFORE & AFTER LANDSLIDE IMAGES FROM NATIONAL REMOTE SENSING CENTER (NRSC)

The Darjeeling district, particularly the Kurseong and Mirik subdivisions, experiences extremely high annual rainfall, averaging over $3000\text{ mm}$. This concentrated precipitation, which falls largely between May and October, makes the region highly susceptible to recurrent landslides, resulting in a long history of such events:
September 1899 (72 fatalities reported in the region).
October 1968 (A massive landslide event combined with a great flood, resulting in over 667 fatalities in Darjeeling, Kalimpong, Teesta Bazar, Lebong, and other areas). Covered in our blog, see here.
June-July 2015: Landslides occurred in Mirik, Tingling, Nimki Dara, and Sukhia Pokhari. Covered in our blog, see here.
October 2025 Disaster: Relentless overnight rainfall on October 4 and 5, 2025, triggered one of the worst recent landslide disasters. Rainfall data of the event is given below:

Fatalities
As per media reports 32 people lost their lives in the deluge with 21 people dying in Darjeeling and 9 & 2 losing their lives in Jalpaiguri and Cooch Behar respectively.

Damage
The disaster damaged 81 roads, 11 bridges, innumerable culverts. It breached 1128m of embankments and washed away 12,680m of river protection works were washed away. Electrical infrastructure was also badly damaged with 272 transformers and 1340 poles being restored till 16Oct2025. Several schools, health centers and drinking water systems were also damaged. Massive damage was reported to the tea industry as well.The tables below will be updated:

Fatal Landslides 

1. Toklang Dara Gaon (Coords: 26.869383N, 88.192072E), Mirik subdivision, Darjeeling district. ('Gaon' is 'Village' in Nepali/Hindi)

Four members of a family were killed by the landslide at this home on 05Oct2025

a. Fatalities: Four — all members of a family who had returned to their home in Taklong  from Salbari, Siliguri, after eight years to celebrate the Dasain festival together.
b. Time of Occurrence: Around 3 a.m. on 05Oct2025.
c. Details: This large landslide occurred during intense thundershowers which moved in from Nepal on 04Oct2025 afternoon. According to local residents, a huge boulder perched on the hilltop — which had earlier been reported to both the local administration and the media — was dislodged by the heavy rainfall, triggering the disaster. Locals also pointed out that inadequate drainage on a newly constructed road above the site had added weight to the slope crown, contributing to the failure.
d. Damage: In addition to the four fatalities, several livestock were lost, and four houses — including a large building — were damaged.
During their survey, the SaveTheHills (STH) team observed numerous landslides along nearby roads, underscoring how road construction and drainage issues remain major triggers for slope failures in the Himalayan terrain.

    Toklang Dara Village (gaon) in Mirik. The hills in the distant are in Nepal

Drone image of the large landslide at Toklang  Dara (Mirik) which
killed 4 people on 05Oct2025.

Large boulders which were dislodged by the intense rain caused immense damage to the village besides the fatalities.

2. Jasbeer Gaon (Coords: 26.895N, 88.2064E) Mirik subdivision, Darjeeling district. ('Gaon' is 'Village' in Nepali/Hindi)

a. Fatalities: Two (husband and wife killed in the landslide - the daughter, aged 15, survived)
b. Time of Occurrence: Around 3 a.m. on 05Oct2025.
c. Details and damage: This massive landslide at Jasbir Gaon extends nearly 1,200 metres down to the Rangbhang River (see map above). According to local residents, a fissure that appeared on the road at the crown of the slope allowed water to seep in, eventually triggering the collapse.
The impact was devastating: once-flourishing orange orchards were wiped out, homes and livestock were lost, and two lives were tragically claimed. The disaster has left deep scars on the landscape and on the community’s livelihood. Many displaced families are now taking shelter in a relief camp at Soureni Bazar, Mirik.

Drone image of Jasbir village landslide near the crown of the landslide.

Drone image of the landslide where it meets Rangbhang river at the base of the mountain. The slide is more than 1.2km in length from the crown (top) to the toe (bottom).

Jasbir Gaon fatal landslide. Two people lost their lives in this area in the early hours of 
05Oct25. In just a few minutes, the massive landslide swept through the slope, turning once-bountiful orange orchards into a barren, rocky wasteland.

Rangbhang river below Jasbir Gaon. The overnight rainfall on 04/05Oct2025 transformed this tiny stream into a raging torrent which gouged out large parts of the valley in its path.

3. Bishnulal Gaon, 11th Mile, Mirik subdivision (Coord 26.89512N 88.17635E)

a. Fatalities: Two of a family (son 9yrs, niece 11yrs of Rabin Chhetri)
b. Time of occurrence: Early hours of 05Oct2025.
c.  Details: Tragedy struck a home at Mirik when a landslide claimed the lives of a nine-year-old son and eleven-year-old niece of Rabin Chettri. The family’s house was completely destroyed, and their neighbor’s home was left half-buried under the debris. Continuous rainfall since the previous evening had saturated the already unstable slope. Just a year earlier, a kutcha road had been hastily constructed along the crown of the hill, using heavy machinery and without any retaining walls or proper drainage which according to Rabin may have caused the landslide. The presence of four borewells at the toe of the slope, coupled with waterlogging, may have further destabilized the ground. When the slope finally gave way around 3:30 a.m., the debris not only engulfed the houses but also buried the borewells, cutting off water access for the entire neighborhood.

Drone image of the slope failure and where two children died at 11th Mile, Mirik on 05Oct2025.

Frontal view of a smashed home where the fatalities occurred.

Partly buried borewell at the base of the landslide. Locals suspect that the water from these wells may have exacerbated the slope failure. Right now, drinking water is a problem for the community in the area because the borewells are non-functional.

Drone image of the landslide gives a clue as to what may have caused the landslide. On the extreme left, there appears to be a jhora or stream which could have led to the slope failure. Notice the reddish color of the soil and the absence of any boulders and rocks.

4. Lakeside landslide, Mirik municipality (Coords:26.89130, 88.18340)
a. Fatalities: Three of a family
b. Time of occurrence: At around 3.00am on 05Oct2025.
c. Details: The family members that the STH team talked with were incredulous that a landslide had taken place in their area at all. They clearly said that the area had no instability or drainage problem and that the only reason that the small slip had taken place was that soil from a nearby construction had been dumped above their home and that during heavy rainfall, this soil had  slid down in the early hours of the 05Oct2025, and extinguished the lives of 3 members of the family. In fact, the whole event had occurred so quietly that they only discovered the landslide and the death of their members at around 6am on 05Oct2025.

Where three lives were snuffed out at around 3am on 05Oct2025 Lakeside, Mirik.

Notice the red soil of the area which many locals say is the reason why Mirik is so landslide prone. The landslide at 3 am of 05Oct2025 went completely unnoticed by other members of the family who only discovered it later at around 6am. By that time, two elders of the family and a relative who was visiting them from Nepal had been dead for several hours, buried by the red soil in a small landslip. 

The red, granular soil tends to lose its cohesion and frictional strength when it becomes wet or moist.

STH team interviewing family members at Lakeside, Mirik during their survey.

Report on fatal and other landslides will be continued.

Report by STH Survey team
Praveen Chhetri (all drone images and photographs): junkeristudio@gmail.com
Steve Rai(interviews and videos with Praveen)
Shreya Gurung (Interviews): shreyagurung07@gmail.com
Yukta Acharya (Interviews and records): yuktaa1999@gmail.com

with sincere thanks and appreciation to Roshan, Rajen bhai and Priya of Darjeeling Himalaya Initiative (DHI)
and also to Aachal (Anugyalaya DDSSS) for helping with resource persons and information.

Praful Rao
savethehills@gmail.com
9475033744

October 2021 Rainfall data of some towns in the Darjeeling and Sikkim Himalayas

 The deluge of 18-19October 2021

Landslide occurrences for the month of Ocober 2021 along the route from Kalimpong to Lava have been compiled in our presentation here

PS: Deep regrets for the delay in this report - it is just that STH uses another social media platform ie What's App 'Hazard Alerts 1 & 2' for reporting weather, rainfall, landslide activity and so on.
What's App is an extremely popular social networking tool in this part of the world and STH has been making use of it extensively for the last 4 years as a medium to report on disaster related information.

 

Shreya Gurung
Praful Rao
SaveTheHills
Kalimpong district
Darjeeling - Sikkim Himalayas

The landslides of Darjeeling town (13Jun2020) - human factor also a trigger?

The SW monsoons finally arrived over the Darjeeling - Sikkim Himalaya on 12Jun2020.
Darjeeling town, received 105mm of rain over a approx 36 hour period, most of it coming down on 12Jun in intense bursts. Between 11-13Jun, Kurseong clocked an astounding 299 mm of rain and this not unusual since our experience shows that Kurseong certainly receives some of the heaviest rainfall in the region.
Six of the landslides which took place within the Municipal Limits of Darjeeling are shown in the map:-

Coordinates of these landslides and two others which are known to have taken place at Kurseong and Mungpoo are given below:-

Images of the landslides at Mungpoo and Sivitar T.E, Kurseong are placed below:-

Rainfall data of 2020 for our region is placed below:-

From the rainfall data it is very evident that, except for Gangtok ie East and North Sikkim, the whole region has been deficient in rainfall not only in 2020 but from the end of the monsoon season in 2019. As such I wonder how 6 landslips (small landslides) were triggered by the first burst of heavy rain (109mm) in Darjeeling town?
It is not abnormal to receive 100mm of rain over a 24hr period during the monsoons, what is abnormal is that this rain coming after a prolonged dry period caused so many landslips in Darjeeling town.
Each of those slope failures were capable of taking human life and our experience over the years has been that it is these small landslides in an urban setting which cause most of the fatal landslides. Saying so, I am painfully reminded of a fatal landslide barely 5 mins walk from my home in Jun2010, at Tirpai Kalimpong when it rained only 45mm overnight. It snuffed out the lives of a young mother and her 2 school going children.
In saying so, I must point out that occurring in densely populated urban settings, the trigger for the  landslide always has a human component and in most cases it boils down to managing our drainage system well. The high volumes of surface runoff from the intense rain in our towns must be drained away quickly and safely - otherwise they are bound to do mischief.

Praful Rao,
Kalimpong district
Darjeeling-Sikkim Himalaya

Rainfall data of Darjeeling-Sikkim Himalaya : March 2017

The precipitation of Mar2017 was a welcome phenomenon. In our region the rainfall,snow and even the hail was moderate with no landslides or casualties reported and the rain brought a relief from the forest fires, the acute water shortage and came as a welcome break for those involved in farming and horticulture.
And even though IMD predicts higher than normal temps in our region in the pre-monsoon period, temperatures here are below normal, ranging from cool to even cold.
It snowed in Sandakhpu , Darjeeling around the 11Mar2017 (see image below).

The most disconcerting event was of course the 4.5M earthquake of 27Mar2017 epi-centred 25km northeast of Kalimpong, near Pakyong (Sikkim) - see previous post.

Rainfall data collection and tabulation - Rohan Rao

Praful Rao,
Kalimpong district
Darjeeling-Sikkim Himalaya

Events of Note : GSI/Govt of Bengal Initiative on 'Landslide Hazard Awareness' in Darjeeling district

Reference is made to this
Subsequent to the two day program conducted last year in Darjeeling, the GSI and Govt of Bengal are launching another series of contact programs at various places in Darjeeling district (see program above).
Considering that this region is one of the most landslide prone in the country (see map below), I find this initiative laudable. I only hope there is a good response from the local people and officials (which was sadly missing last year).
It will be a pity if political interference impedes disaster awareness programs and initiatives.

Praful Rao
Kalimpong,
Dist Darjeeling