It happened in the early morning hours on Thursday at St. Anthony of Padua Parish Catholic School and Pre-School on East Erie Avenue.
When they got there, firefighters found heavy smoke and fire coming from the middle building on campus.
Lorain firefighters extinguished the fire, but the building that houses the gym and cafeteria suffered from over $1 million in smoke and fire damage.
Investigators say no one was inside the school at the time and there were no injuries.
State Fire Marshal investigators ruled the fire an arson, but no arrests have been made in the case.
Now, there’s a $5,000 reward for information leading to an arrest.
Anyone who has information on the incident should contact the State Fire Marshal’s tip line at 800-589-2728.