Tenants of a building in Ruiru were lucky to have evacuated early on Sunday, before the building collapsed on Monday at 4am.
Residents raised alarm after they saw visible cracks on Sunday.
The building is opposite Ruiru Police station.
Tenants on Sunday tried to save some of their household items.
Kiambu Governor Kimani Wamatangi who visited the site on Sunday said the building was visibly weak and had all indications that its construction was not done well.
He had said the building will remain closed awaiting an assessment, only for it to cave in later.
"We will not allow anybody to occupy poorly constructed houses as they are dangerous and this Ruiru house is one of them," Wamatangi said.