More than 100 firefighters tackled a massive warehouse blaze in Perivale on Saturday evening.
Thick plumes of smoke billowed across London from the fire which began at around 6.45pm in Wadsworth Road.
The raging inferno broke out on a site of "mixed factory units".
The smoke could be seen for miles, with one picture showing how it is visible in Wembley Stadium.
London Fire Brigade (LFB) revealed that around 30 people left the building before crews arrived and there are no reports of any injuries.
The fire service said at the time the blaze is producing "a lot of smoke", and urged residents to "close windows and doors".
In an earlier statement LFB said: "Around 100 firefighters and officers are currently tackling a fire at a warehouse on Wadsworth Rd, Perivale.
"All of the roof and the first floor is currently alight.
"The fire is producing a lot of smoke and the brigade has advised locals to keep windows and doors shut.
"The brigade was called at 18.52.
"The cause of the fire is not known at this stage. "
Station Manager Jeff Lisle said: "Crews are working very hard in difficult conditions.
"Firefighters are using aerial ladder platforms to tackle the fire from numerous vantage points and to ensure the blaze doesn’t spread to neighbouring warehouses. While we are making excellent progress, we expect to work on this fire into the night.
“This isn’t a residential area but the smoke is travelling quite a distance so do keep windows and doors shut if you are local.”
LFB said on Twitter that they expected to be tackling the fire "well into the night". At around midnight they posted that the fire was "under control" and crews would be "damping down hot spots for some time".