At least 10 people were killed, nine of them from electrocution, as torrential overnight rain - among the heaviest in four decades - left Kolkata and adjoining districts paralysed on Tuesday, disrupting air, rail and road transport, shutting educational institutions, and prompting the state government to advance Puja holidays.
The deluge - 251.4 mm in less than 24 hours - was the highest since 1986 and sixth-highest single-day rainfall in the last 137 years, only behind the record 369.6 mm in 1978, 253 mm in 1888, and 259.5, 98 years later.
On Tuesday, the maximum hourly rainfall of 98 mm was recorded between 3 am and 4 am, the India Meteorological Department (IMD) said, clarifying that it does not satisfy the cloudburst criteria.
According to the IMD, rainfall exceeding 100 mm in an hour over a 20 to 30 sq km area is defined as a cloudburst.
The deluge, though, turned arterial roads into rivers, snapping Metro and train services, and throwing air travel into disarray as the city gasped for normalcy ahead of Bengal biggest festival-Durga Puja-next week.
Chief Minister Mamata Banerjee described the downpour as "unprecedented", blaming poor dredging of the Farakka barrage and lapses by private power utility CESC for the deaths, while appealing to people to stay indoors.
"I have never seen rain like this. In all, ten people have died, out of which nine deaths were caused by electrocution from unattended live cables. Eight people died in Kolkata and two others in adjoining areas of Shashan in North 24 Parganas and Amtala in South 24 Parganas. It is so unfortunate," Banerjee said during a virtual address.
Taking to X, she wrote, "I express my deepest condolences to the families who lost their kin on account of negligence of the CESC. There can be no compensation for death and no alternative to life. Yet, we will ensure employment for one member of each of the victim families. I have asked the CESC to offer compensation as well. These families deserve this compensation besides our heartfelt empathy." Banerjee also pointed fingers at the Damodar Valley Corporation, holding it responsible in parts for the distress and suffering of citizens.
"The state was already reeling under floods and its rivers and canals filled to capacity on account of the unilateral water release by the DVC. Large volumes of water from Bihar and Uttar Pradesh poured in from the Farakka Barrage which already was crisis-ridden due to lack of dredging (of river beds). On top of that, this massive downpour happened. I am keeping a close watch on the situation through the (Kolkata) mayor and the chief secretary," she added in her post.
Electricity in Kolkata and adjoining areas is supplied by CESC, and not the state government, she said later in her address, adding: "It is their duty to ensure people do not suffer because of this. They will do business here, but will not they modernise? They should send people to the field and fix this." The authorities announced all government-run educational institutions will remain closed on September 24 and 25, effectively advancing the Puja holidays, which was scheduled to commence from September 26, by two days.
The deluge forced Durga Puja organisers to defer inaugurations of community pujas as the calamity wreaked serious damage to marquees that are complete or nearly so, and pushed back the intricate installation art in pandals by artisans.
For lakhs of residents, Tuesday dawned to a city under siege by water. In south Kolkata's Garia and Jodhpur Park, residents were unpleasantly surprised to find knee-to-waist-deep water in living rooms, ground floors and shops.
Many frantically shifted furniture to upper floors, while traders at Gariahat and College Street tried in vain to salvage soaked stocks of books, garments and electronics.
Motorcycles and cars bobbed like abandoned boats, buses broke down mid-way, and commuters trudged barefoot through filthy floodwaters clutching their belongings over their heads.
"I had to walk nearly three kilometres in waist-deep water from Lake Gardens to Rashbehari Avenue. I don't know how I will get back home," said office-goer Rupa Chatterjee.
Those stranded in app cabs complained of exorbitant surge fares, while many others waited for hours in vain at bus stops.
Mayor and Urban Development Minister Firhad Hakim admitted that most parts of the city were waterlogged despite continuous pumping by civic teams.
"The canals and rivers are full of water, and every time water is drained out, more comes inside the city. The situation may not improve until after tonight's low tide," he said.
Across the city, arterial roads such as EM Bypass, AJC Bose Road and Central Avenue turned into rivers, while traffic crawled for hours at key intersections like Park Circus, Gariahat, Behala and College Street.
Metro services were suspended between Shahid Khudiram and Maidan stations since morning, with truncated runs only on the Dakshineswar-Maidan stretch. Eastern Railway halted movement in the Sealdah south section, while skeletal services were attempted in the north and main sections.
Air travel was also hit hard. At least 90 flights were cancelled and over 90 others delayed from the NSC Bose International Airport till evening.
Adding to apprehensions of puja organisers and prospective pandal hoppers alike, the Met office warned that another similar system is likely to form on September 25, on the eve of the Pujas, and bring showers to the region.
Discover the latest Business News, Sensex, and Nifty updates. Obtain Personal Finance insights, tax queries, and expert opinions on Moneycontrol or download the Moneycontrol App to stay updated!
Find the best of Al News in one place, specially curated for you every weekend.
Stay on top of the latest tech trends and biggest startup news.