TUCSON, Ariz. — It was a fire big enough to be seen across a wide swath of Tucson.
About 5,000 bales of hay caught fire at the San Xavier Co-Operative Farm on the edge of the Tohono O'odham Nation Tuesday night.
The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) sent investigators to the farm Wednesday, but that doesn't mean the fire is suspicious.
Twenty thousand bales of hay can make for a very big fire. Workers at the San Xavier Co-Op Farm noticed the blaze about 5:30 p.m. Tuesday. It didn't take long for the blaze to become such a challenge to fight that five fire departments joined in the effort.
Once most of the blaze was put down, firefighters from the Tohono O'odham Fire Department worked to break up the smoldering hay and make sure it would not rekindle and flare up all over again.
The hay from the farm fed a lot of animals across this region. People would come to buy hay to feed horses at their homes, along with farmers and ranchers on the Tohono O'odham Nation that would use it to feed their livestock.
The hay and the structure that held it are total losses. The farm does grow other things to sell but the fire put those operations on hold.
Farm manager Gary Chavez says, “Because the fire was so close to our store -- our retail store that also is not open -- so all parts of our operation are at a halt," farm manager Gary Chavez said. "As you can see, we have a lot of smoke damage and it continues to be real smoky here.”
Chavez thinks it will probably sometime next week before the fire department gives the all-clear to reopen the rest of the farm to the public.
Some hay stored away from the main shed did avoid the fire and none of the workers or animals at the farm were hurt.
While the cause is still under investigation one possibility is the fire was started by nature. Hay is prone to spontaneous combustion. If it gets a little wet bacteria can grow. They create chemical reactions that add enough heat to make the hay catch fire.
Investigators have not officially determined what caused the fire.
An earlier version of this story included a higher estimate from authorities about the number of hay bales burned.