Fire crews had requested the Environment Agency to attend the fire at a building on Collaton Lane in Tavistock, to help control a diesel spillage.
Western Power has also been at the site and disconnected the electricity to help make it safe.
At 0700, a cordon has been put around the area and fire crews were monitoring the incident from a safe distance because of the volatile nature of acetylene cylinders.
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The RSPCA is working on a prevention message to help resolve the increase of abuse of horses and donkeys within the west country.
Outbreaks of rain and drizzle could turn heavy at times, with foggy conditions persisting over main coastal areas. Highs of 13 or 14 C
There will be outbreaks of rain and drizzle today which could turn heavy at times. Maximum temperatures around 13 or 14 degrees