A fridge warehouse and factory has been completely destroyed after a fire tore through the two-storey building.
Plumes of thick black smoke were seen pouring from the Liebherr building in Newport Pagnell, Buckinghamshire.
People living nearby were told to keep doors and windows closed while nearly 60 firefighters battled to bring the blaze under control.
A spokesman for Buckinghamshire Fire and Rescue Service, which sent crews from Newport Pagnell and six neighbouring towns to the scene, said smoke from the fire could be seen from miles away.
Workers in nearby factories and offices were able to get out safely when the blaze was discovered and no one was injured, he said.
Emergency services received nearly 50 calls from members of the public shortly after the fire broke out.
Kam Singh, a local singer-songwriter, tweeted he had "never seen anything like this before", adding: "Hope everyone is safe."
Another Twitter user, Ian Christie, said he could see the smoke from Milton Keynes city centre, while Selina Lee posted : "Massive fire in Newport Pagnell. Huge cloud of smoke covering the town. Chaos."
The fire was extinguished within four hours, although incident commander Steve Wells said crews would remain at the scene "for some considerable time".
A spokesman for Thames Valley Police said several local roads were closed, adding that drivers had been told to avoid the area.
According to its website, Liebherr makes refrigerators, freezers and wine coolers for both the domestic and commercial markets.
Its products are sold across Europe.
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