Ten fire engines and 72 firefighters and officers tackled a fire in a industrial yard on Whitewebbs Lane in Enfield.
A 150m by 100m stack of wooden pallets and a warehouse were destroyed by the blaze. Eight cars, seven forklift trucks, six lorries and three caravans were also badly damaged.
Two men evacuated a caravan before the Brigade arrived. They were both uninjured. Around 35 propane gas cylinders were removed from the site.
Heavy smoke filled sky and motorists on M25 junction 24 and 25 were asked to take extra care.
Deputy Assistant Commissioner Graham Ellis who was at the scene said:
“This is a difficult fire to fight but crews worked exceptionally hard to bring it under control. Firefighters will remain at the scene throughout the morning damping down pockets of fire."
The Brigade was called at 0203 and the fire was under control by 0559. Fire crews from Enfield, Edmonton and surrounding fire stations attended the incident. The cause of the fire is not known at this stage.