Videos shared online showed a dramatic crash and huge clouds of dust as the 16-storey building came down in the densely populated business and residential area of Eastleigh.
The building lay in a pile of rubble as search and rescue teams arrived on the scene and struggled to start accessing the site which was jammed between other high-rise buildings.
“Eleven shops on the ground floor and in the basement were occupied at the time of the collapse. Seven people have been reported missing,” Interior Minister Kipchumba Murkomen posted on X late Friday.
Murkomen said 66 of the 67 people working on the site had escaped unharmed, while one was injured.
Earlier, police said they had already rescued one woman from the rubble, and could hear the voice of another.
“The contractors and the engineers are supposed to ensure that the works are followed by professionals. But most are not,” Bibiye Mahmoud, president of the Institution of Engineering Technology of Kenya, told AFP at the scene.
“This is why we are seeing these catastrophes… There is no accountability,” she added.
Kenya’s National Building Inspectorate report found that 87 percent of buildings audited nationwide last year failed to meet standards or lacked the required approvals.
“Our concern is to save lives,” Nairobi Governor Johnson Sakaja told reporters, adding: “This building has no occupation certificate… this has potentially cost lives.”
An occupation certificate is essentially the authority’s formal sign-off that a building is safe and legally fit to be occupied.
John Ogallo, vice-president of the Institution of Engineers of Kenya, who was also at the site, said there were warning signs about the building.
“People here are saying distresses were observed, like cracks,” before it collapsed, he told reporters.
If you build with the wrong materials, “it becomes a time bomb,” he added.
Nairobi is undergoing a rapid construction boom, with high-rise buildings springing up across the city, particularly in Eastleigh which is known for its busy market areas and as a hub for the Somali community.
The number of buildings completed annually in Nairobi rose from 20,025 in 2022 to 25,090 last year, according to its statistics bureau, as east Africa’s leading business hub sucks in people from rural areas and neighbouring countries.
Local media reported looting immediately after the collapse, which happened around lunchtime.
AFP saw police use tear gas to disperse crowds gathering near the site.
There were 86 building collapses between 2009 and 2019 in Nairobi, killing an estimated 200 people, according to a report by the Kenya Institute for Public Policy Research and Analysis.
Corruption has allowed contractors to cut corners or bypass regulations.
Five people were killed when a six-storey building collapsed in a town on the outskirts of Nairobi in September 2022.
In April 2016, 49 people died when a six-floor apartment building crumbled in the northeast of the capital after days of heavy rain caused floods and landslides. (AFP)