Two loud explosions shook the ground in March as a workshop on an industrial estate went up in flames.
Firefighters tackled the blaze at Force One in Longhill Road just after 4pm this afternoon (October 31).
Plumes of black smoke could be seen bellowing into the sky from across the town.
Explosions of what were thought to be gas cylinders could be heard as crews arrived to cordon off the area.
Workers from nearby businesses looked on shell-shocked as roaring orange flames could be seen from the roadside.
One woman, whose grandfather owns the building next to Force One, said: "I was in town shopping when I could see the smoke.
"We dashed down as we feared it could be our building when we heard about it being the industrial estate.
"It appears that our building is safe but the storage shed from Force One is on fire.
"I think they keep their suction equipment in storage in there."
Homes near to the blaze were evacuated as firefighters warned pedestrians to stay back near HMP Whitemoor.
A police spokesman said: "Officers are currently at the scene and the road is closed at the Elm Road junction with Longhill Road.
A small number of houses have been evacuated as a safety precaution."
A worker from SDM Fabrication, in the site opposite Force One, said: "It started about 45 minutes ago. We just looked out the windows and couldn't believe the black smoke we were seeing.
"I just hope it hasn't taken any vehicles or the building near it too."
Crews from March, Wisbech, Chatteris, the North roaming fire engine and a water carrier from Ramsey remain at the scene.
"The cause of the fire will be investigated once the fire has been extinguished," said a spokesman for Cambridgeshire fire service.
Force One operates vacuum excavator hire services nationwide.
A nearby worker said: "We were in the yard next door and we were moved out but we couldn't get anywhere due to the volume of the fire engines in the area."
One man said that he could see and smell the smoke from Thorney Toll garage - over five miles away.
Others said that they could see flames from Chatteris, Littleport and Welney.
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