Fire near Heathrow Airport
Seventy-five fire fighters have been putting out 50,000 tonnes of burning wood chip just north of Heathrow Airport.
The fire started at around 3.30am on Tuesday.
Crews are protecting two 20,000 litre tanks of diesel.
Flights aren't affected.
On Monday night around 3000 people were evacuated after a fire at a mechanics yard in Harrow.