An investigation is under way into the cause of a fire at a factory in Derbyshire that saw about 20 people forced to leave their nearby homes.
Fire crews were called to Technique Composites on Peasehill Road in Ripley on Sunday evening as flames ripped through the roof.
Firefighters were concerned a gas cylinder inside the building may explode so they cordoned off the area.
Residents were eventually allowed back into their homes at about midnight.
Derbyshire Fire and Rescue spokesman David Hutchinson said the crews had to take a cautious approach to the fire because of the gas cylinder.
He said: "Acetylene cylinders do pose quite a substantial hazard to the fire service and the public.
"It's a very unstable gas and when involved in fire, we have to apply cooling procedures for 24 hours."
Scott Bell, who lives near the factory, said he first noticed thick smoke coming from the building.
"First thing I knew, I was sat in the living room and I could see thick black smoke in front of the window," he said.
"I went outside and heard some bangs, it sounded like fireworks to start with.
"I could see the black smoke coming into the garden and the flames were reaching up high.
"A few minutes later there were some loud explosions."
A spokesman for Derbyshire Fire and Rescue Service said an investigation would be carried out later.