Six fire engines and around 40 firefighters were called to a fire at an office building on Snowden Street in Shoreditch.
An air conditioning unit in a maintenance area on the 12th floor of the building was destroyed by fire. Around 20 people left the building before the Brigade arrived. There were no reports of any injuries.
Firefighters wearing breathing apparatus used thermal imaging cameras to locate the fire and quickly bring it under control.
The Brigade was called at 0833 and the fire was under control by 0942. Fire crews from Whitechapel, Dowgate, Bethnal Green, Shadwell, Islington and Dockhead fire stations attended the scene.
The Brigade’s Fire Investigators believe the fire was accidental and caused by an electrical fault in the air heating system.