Sixty firefighters from throughout the region were invited to take part in the two-day exercise to learn everything from fire behavior to influencing a fire's path.
"We want to train as we fight," Redlands Fire Battalion Chief Jim Topoleski said. "We can't do that when there is no smoke and there is no heat present. So doing it in these controlled environments, it benefits us in order to do live fire training when we actually get responded to a fire."
The building, which is slated for demolition, was donated just so crews could set it on fire and train.
"You have paints, varnishes and finishes inside, so you have a really good opportunity to watch paint bubbling and blistering and watching the off-gassing to start ignite, which you don't have that opportunity in the burned buildings," said Capt. Josh Janssen of CalFire's Yucaipa station.
During the drills, firefighters took turns rotating in and out of the burning building until everyone had a chance to tackle the blaze.
Because of budget cuts, training simulations have become less frequent.
"We're going to less fires than we used to in the past, but the fires are more dangerous than they've ever been before with the way the products are being build now," Janssen said.