A five-story building packed with university students collapsed without warning in South Delhi on Sunday afternoon, killing at least six people and trapping dozens more under a mountain of concrete and rebar as rescue crews worked through the night with earthmovers and sniffer dogs.

The building, in the Satya Niketan neighborhood near Delhi University — a dense pocket of budget student housing — came down around midday local time on September 6. At least six people were confirmed dead at AIIMS hospital, five of them pronounced dead on arrival, according to Al Jazeera's reporting from the scene. Six more survivors were pulled out alive and hospitalized in stable condition. Officials said as many as 40 people may have been inside or near the structure when it gave way.

Basement water blamed for the collapse

Delhi Chief Minister Rekha Gupta said preliminary findings point to water accumulating in the building's basement during ongoing repair work, which is believed to have undermined the roughly 50-year-old structure until it buckled. Rescue teams used heavy machinery alongside hand-digging through the night to reach anyone still trapped in the rubble, per a Reuters report.

Delhi Police have registered a formal criminal complaint (FIR) against the building's owner, who has not been located, and are treating the collapse as a possible case of negligence tied to unauthorized construction or repair work, according to the Deccan Herald. Prime Minister Narendra Modi's office issued condolences to the victims' families Sunday evening.

WATER ACCUMULATION IN THE BASEMENT DURING REPAIR WORK CAUSED THE STRUCTURE TO FAIL — DELHI CM REKHA GUPTA

Building collapses are a grim recurring hazard in Indian cities during and after the monsoon season, when saturated ground and aging, often illegally modified structures give way with little warning. Satya Niketan's cramped lanes of converted houses are popular with out-of-town students for their cheap rents, a combination that housing-safety advocates have long warned leaves tenants especially exposed when landlords cut corners on structural upkeep.

Search-and-rescue operations were still active as of Monday morning, with officials cautioning that the final death toll could rise. Delhi authorities said a broader structural audit of nearby buildings undergoing similar basement work is now under consideration.