STORY: Rescuers pulled several people out of the rubble of a collapsed building in Kenya's capital on Tuesday (May 14).
But, Kenya's Red Cross said, more were likely trapped.
The building had been undergoing demolition in Nairobi's Mathare.
It is one of the city's largest informal settlements.
Planning regulations there are rarely enforced.
The neighborhood was also recently inundated by floods that killed at least 289 people nationwide.
In Mathare, dozens died and thousands were forced to leave their homes after the Mathare River burst its banks.
Authorities have since begun demolishing buildings on flood-prone land in Mathare deemed to be illegal.
The collapsed five-story building was partially demolished by officials a week ago, said Wanjiru Wanjiru of local rights group the Mathare Social Justice Center.
But some residents had remained in their apartments.
