Smoke from the fire can be seen several miles away
Firecrews are in the final stages of putting out a fire at a recycling plant in a former RAF hangar in Lincolnshire.
Thick black smoke could be seen for miles after the fire started at the AWS Eco-plastics factory at Hemswell Cliff at 1500 BST on Tuesday.
Early on Wednesday crews said they were damping down, but expected to be at the scene for at least the rest of the day.
Dave Brocklesby of Lincolnshire Fire and Rescue Service said investigations would begin as soon as it was safe.
He said: "We've got fire investigation officers on site.
"At this time they'll be assisting in firefighting operations and as soon as it's safe to do so they'll start talking to the owners, workers, and we'll try and build a picture up of just what's happened and what's actually caught fire."
The site was evacuated after propane gas cylinders exploded.
The A631 was closed from Harpswell Hill to Caenby Corner as a result of the fire.
Residents were to keep their doors and windows closed to avoid breathing in the smoke.
Witnesses said smoke could be seen from several miles away. One person said the hangar was ablaze from one end to the other.
See footage of the fire and hear how it affected nearby businesses
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