Four fire engines and 21 firefighters and officers were called to a fire in a circus lorry trailer at a car park in Spalding Road, Brent Cross.
Most of the trailer was damaged by fire. A number of propane cylinders were involved and crews cooled them to an ambient temperature.
The Brigade's 999 Control Officers took 38 calls to the fire.
The Brigade was called at 0719 and the fire was under control at 0956. Fire crews from Hendon and West Hampstead fire stations attended the scene.
The cause of the fire is under investigation.