COLOMBO, Sri Lanka — A five-story building under construction in Sri Lanka’s capital collapsed Thursday, killing one and injuring at least 22 people, officials said.

Those injured in the collapse in Colombo have been sent to hospitals, police spokesman Priyantha Jayakody said.

Hundreds of soldiers, police and firefighters were searching for anyone who might be trapped inside the building.

Dr. Anil Jasinghe, head of Colombo’s main hospital said one person rescued from the rubble died. His respiratory system and heartbeat were not functioning when he was admitted to the hospital and efforts to resuscitate him failed, Jasinghe said.

The reason for the collapse was not immediately known.

Sarath Wimalawardena, who works at a nearby construction site, said the building collapsed with a loud sound that was followed by an enormous cloud of dust. He said people in the area helped evacuate the injured before police and firefighters arrived.