Around 40 residents were evacuated from their homes as up to 100 firefighters tackled a large blaze at an industrial estate on Saturday
Part of a large warehouse was 80 per cent alight when fire crews arrived at the Rainbow Industrial Estate in Trout Road, West Drayton, west London, just after 11am.
Around 30 employees from the industrial units and 40 people from neighbouring homes were evacuated "as a precaution" amid fears that a gas cylinder could be involved.
London Fire Brigade (LFB) said five hose jets and two aerial ladders were used to fight the flames as stacks of dense, black smoke belched above the warehouse.
Station manager Matthew Burrows said: "Our crews are working hard to get this large fire under control as soon as possible. We are tackling the blaze from three different sides to prevent it from spreading to other units.
"A number of nearby residential properties have been evacuated as a precaution as one gas cylinder is involved in the fire. We take extra precaution with fires involving cylinders because some cylinders can explode when exposed to heat."
Crews from Hillingdon and surrounding fire stations attended. A brigade spokesman said the cause of the fire was not known.
A Hillingdon Council spokeswoman said: "Some people gathered in the local library and we have kept that open for a bit longer. People have been having to park further away from their homes, so we have asked parking wardens to be less stringent with their ticketing."
Firecrews are still on the scene this morning.