Associated Press video showed people cheering as one dust-covered person was carried away on a stretcher, one arm outstretched. Shortly afterward the crowd hushed as another person was carried away but covered completely by a blanket.
Nairobi county police chief Philip Ndolo said at least 10 people had been rescued by residents of Tassia estate using their bare hands. Eight people had been taken to a hospital, Nairobi regional commissioner Wilson Njenga said.
“Tragedy has struck us again," public works official Gordon Kihalangwa said. “Some people have been trapped inside and we are doing our best to free them."
It was not immediately clear what caused the morning collapse. Njenga said 57 rooms had been rented out in the building. The Red Cross said 22 families lived there. Njenga said the building's owner was “not available" and not living there.
Hundreds of people gathered to watch from nearby buildings as emergency responders prodded at the pancaked concrete structure. Military personnel arrived to assist. Heavy equipment was at the site but Njenga said starting any excavation could cause more damage if anyone alive remained in the ruins.
Medical workers set up an impromptu center in tin-roofed stalls nearby while a line of ambulances waited. One covered body was seen there on the ground.
Building collapses are common in Nairobi, where housing is in high demand and unscrupulous developers often bypass regulations.
After eight buildings collapsed and killed 15 people in Kenya in 2015, President Uhuru Kenyatta ordered an audit of all the country’s buildings to see if they were up to code. The National Construction Authority found that 58 percent of buildings in Nairobi were unfit for habitation.