Sympathisers trooped to 32, Ibadan Street, where a three-storey building collapsed last night at Ebute-Meta, Lagos mainland.
Many occupants were believed to be trapped in the building, which caved in at about 9.48pm yesterday.
The incident was confirmed by an official of the Lagos State Emergency Management Agency (LASEMA).
The official said that a rescue team from Lagos State Fire Service, Lagos State Ambulance Service (LASAMBUS) and the State Building Control Agency (LASBCA) had arrived the scene.
The number of residents trapped in the building could not be ascertained. But 11 persons were rescued.