Crews rushed to the 200 block of Martin's Corner Road in West Caln on Tuesday and immediately "mounted an offensive attack on the fire," according to the Wagontown Fire Company.
The fire department extinguished the blaze within several hours with help from area fire companies.
While no people or animals were injured, the fire severely damaged the barn, according to a GoFundMe launched on behalf of the victims, Don and Gail.
"This family goes over and beyond to help people out without even being asked. They personally helped out my family and it's very much appreciated," fundraiser organizer Amy Clark writes.
"So if we can come together as a community and let them know that they are not alone. This was not just a barn it was their business, their source of income."
Nearly $300 had been donated as of Wednesday night to help the owners recover from their "devastating" loss.
Click here to view/donate to "Don and Gail's Barn Fire."
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