The fire started around 11:30 p.m. Thursday at Jay Littleton Ball Park. Responding firefighters encountered massive flames coming from the stadium and dugout, but little could be done to save it. No injuries were reported.
"Unfortunately, the extent of the fire... has ended with a complete loss of of our stadium," said Deputy Chief Michael Wedell with the Ontario Fire Department.
The historic baseball field was built in the 1930s with a wooden frame grandstand.
It's owned by the city and operated by the public works agency. It was designated a historic landmark back in 2003.
It's been renovated several times, but officials said there was still likely a lot of old wood in the structure, which is dry and burns quickly.
Given its longstanding history, community members and baseball fans alike were heartbroken about the loss of the baseball field.
"It went up like a box of matches... You're literally watching history burn," said Aaron Matthiesen, president of the Ontario Eastern Little League.
The field was featured in several Hollywood productions, including the 1992 film "A League of Their Own" starring Tom Hanks, Madonna, Rosie O'Donnell and Geena Davis.
"The dugout here on the third baseline is where Tom Hanks had his iconic line: 'There's no crying in baseball!'," Matthiesen added.
In recent years, it wasn't as glamorous as the stadium fell in disarray.
"A lot of that has to do with the fact that the homeless (were) going in and breaking things and continually causing issues that made it unsafe for our players to be on the field and unsafe for our spectators to be in the stands," he added.
Matthiesen believes that's part of what happened Thursday night.
Fire officials have not determined the official cause of the fire, but arson investigators were combing through the burnt remains Friday morning.
"That, of course, is going to be one of the potential causes but, at this point, there's no indication... that that would be the cause," Wedell added.