Firefighters were called to a partial building collapse at a school on Brentfield Road in Brent.
The top half of a brick tower adjacent to a single-storey sports hall at the rear of the school collapsed onto the roof.
Firefighters used thermal imaging cameras to assist in carrying out a search of the building. A 25-metre cordon was put in place as a precaution whilst crews worked to make the scene safe. There were no reports of any injuries.
The Brigade was called at 1229 and the incident was over for firefighters by 1357. One fire engine from Park Royal and two fire rescue units from Heston and East Ham fire stations attended the scene.