The first units arrived at the scene at 7:30 p.m. and saw heavy smoke coming from the roof of a concession area near the right field gate.
Firefighters encountered high heat and heavy smoke as they attacked the fire, which was contained at 7:41 p.m.
There were no injuries.
The fire was determined to be caused by an unattended electrical appliance. Investigators estimate about $200,000 in property and goods damaged or destroyed, out of the $900,000 total estimated value. So firefighters saved an estimated $700,000, or 80 percent, of the value of the building and contents.