A multi-story apartment block in Florida partially collapsed during Thursday's early hours, sparking a major emergency response. It was unclear how many people lived in the building in the town of Surfside -- just north of Miami Beach -- or had been inside at the time. Online videos showed a large portion of the 12-storey building reduced to rubble. Emergency services sent dozens of response units to the scene, near to the local beach. Miami Beach Police Department said its officers were "assisting the Town of Surfside at a partial building collapse." "Multiple police and fire agencies from across Miami-Dade are assisting," the force added. Miami-Dade Fire Rescue said: "Over 80 MDFR units... are on scene with assistance from municipal fire departments." bur-leg/je