A 50-year-old five-storey building housing a boys' PG collapsed in Satya Niketan near Delhi University's South Campus on Sunday, leaving at least five students dead and many trapped, officials said.
Ten people have been pulled out of the debris so far, of whom four were brought dead to the hospital, and one died during treatment.
Three patients remain admitted and are undergoing treatment, while one underwent limb surgery and another was discharged after observation.
A 19-year-old person was also brought to Safdarjung Hospital at 3.05 pm with minor injuries and was admitted for observation, officials said.
Locals claimed that around 40 people were still trapped under the debris of the building, which comprised a basement and five upper floors.
Delhi Chief Minister Rekha Gupta late on Sunday ordered a magisterial probe into the incident.
"Following an on-site review and based on the preliminary assessment, Chief Minister has ordered a Magisterial Inquiry of the incident and FIR against the building owner," Delhi CMO said in a post on X.
Repair work was underway in the basement of the structure, which was used as a paying guest (PG) accommodation, when it collapsed at around 1.30 pm, a senior officer said.
Locals claimed that collection of water over days of rain in the basement had weakened the building's foundation, leading to it eventual collapse.
Teams of Delhi Police, NDRF, Delhi Fire Service and DDMA, along with fire tenders and CATS ambulances, reached the spot and commenced rescue operations.
The area is marked by narrow, congested bylanes lined with eateries and PG accommodations catering mainly to students.
The densely packed buildings and heavy student presence often leave little room for movement, with locals saying most of the students staying in the locality were from Keralam, Haryana and Uttar Pradesh and study at colleges located across the road.
As rescue teams worked through the debris, locals and eyewitnesses also joined the frantic efforts, using their bare hands and whatever tools were available to search for those buried underneath.
A video circulating on social media showed an unconscious youth trapped beneath a slab, with half his face and one hand visible, as locals desperately tried to pull him out.
Delhi Chief Minister Rekha Gupta, Lieutenant Governor Taranjeet Singh Sandhu, Police Commissioner Anurag Kumar, and MP Bansuri Swaraj rushed to the spot after the incident.
Union Home Minister Amit Shah expressed his grief at the deaths.
He said he spoke to the chief minister, the police commissioner, and the NDMA director general for an assessment of the situation on the ground.
The Joint Commissioner of Police, New Delhi Range, DCP Southwest and Additional DCP are supervising the operation, an officer said, adding that the building was known as 'Hostel Daze' and its owner is based in Gurugram.
"The exact number of persons trapped/injured is still not known at present. Further details will be shared as and when confirmed," a statement issued by Delhi Police said.
"The lanes are very congested, and it is difficult for rescue vehicles to reach here faster," a local resident said.
Locals and eyewitnesses said they immediately joined the rescue efforts, using their hands and available tools to remove debris in their search for those trapped underneath.
Delhi Chief Minister Rekha Gupta expressed concern over the incident, adding that teams from DDMA, NDRF, Delhi Fire Services, Delhi Police, MCD, CATS and Civil Defence are carrying out rescue operations on a war footing.
She said the adjacent building has been vacated as a precautionary measure and every possible effort is being made to safely rescue those trapped and provide immediate assistance to the affected families.
"The situation is being closely monitored, and all concerned agencies are working in coordination. The safety and well-being of every citizen remain our highest priority," she said in a post on X.
South Delhi BJP MP Ramvir Singh Bidhuri announced that the government has constituted an inquiry committee to investigate the collapse and initiate strict action against those responsible.
BJP MLA Anil Sharma reached the spot and informed that people are still trapped.
"We are even getting calls from those who are trapped inside. Teams are continuously in touch with those who are trapped inside; we pray to god that all people are safe," he said.
An eyewitness commented that the incident could have been much worse had it occurred on a working day since many students from nearby areas had returned home. "Very few were here," he said.
Delhi has witnessed incessant rain since Friday.
The locals also raised concerns over the condition and maintenance of other buildings in the area, where several houses have been converted into PGs.
Priyanka, who has lived in the area for over two decades, said, "Buildings here are being constructed up to five-six floors. Many houses have been converted into boys' PGs, with the owners shifting elsewhere. They simply name the properties as PGs, take the rent online and leave the area without even checking back."
She added, "I have not seen any maintenance work ever being carried out. Since it was raining, most of the students were inside rooms, while some had gone home as it was the weekend."
The police have advised locals and onlookers to stay away from the site.
Paramilitary has been deployed to ensure unobstructed movement of ambulances.
(With inputs from PTI)
