Ten fire engines and around 70 firefighters tackled a flat fire on Maybury Close in Enfield.
The roof and second floor of a three storey block of flats was destroyed. 14 people left the building before the Brigade arrived. Three children and one adult were taken to hospital as a precaution to be treated for smoke inhalation.
Two of the Brigade's 32-metre turntable ladders were used as water towers to help extinguish the fire from height. The Brigade's Drone Team were also in attendance and provided the Incident Commander with an aerial view of the fire.
Control Officers received the first of 16 calls about the fire at 0519. They mobilised crews from Enfield, Edmonton, Chingford, Tottenham, Woodford, Southgate fire stations to the scene. Two fire engines from Hertfordshire Fire and Rescue Service were also in attendance. The fire was under control by 0806.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.