Four fire engines and 21 firefighters and officers were called to a fire in a basement in Great Windmill Street in Soho.
An electrical substation was damaged by the fire. The building’s sprinkler system operated and extinguished the blaze.
Approximately 40 people left the building before the arrival of the Brigade and firefighters led 20 people from the ground floor to safety. There were no reports of any injuries.
The Brigade was called at 1917 and the fire was under control at 2106. Fire crews from Soho, Euston and Lambeth fire stations attended the scene.
The cause of the fire is under investigation.