Five fire engines and around 35 firefighters were called to reports of smoke in the basement of a restaurant and office block on Regent Street, Marylebone
Smoke was coming from an electricity sub station and filling the basement. Firefighters established that there was no fire and ventilated the room.
Approximately 200 members of public left the office block and restaurant before the Brigade arrived.
The Brigade was called at 1352 and the incident was over for firefighters at 1617. Fire crews from Soho, Euston, and Paddington fire stations attended the scene.