Authorities in Sanford are investigating six suspicious fires, four of which happened overnight within a four hour period and destroyed a historic school house.
State fire investigators believe the fires are the work of an arsonist.
The Little Red School House, built in the 1880s, caught fire early Thursday morning, minutes before a blaze broke out at a nearby house on Maple Street. The home did not appear to sustain significant damage.
Meanwhile, firefighters said a blaze gutted a home on Carriage Cove.
A fourth fire broke out at a house on Hester Avenue near Ronald Regan Boulevard. Flames were contained to the second floor of the home, officials said.
"In all my years of being a firefighter, I've never seen four fires in one night," a Sanford fire official said.
State fire marshals continue to investigate the blazes. They said arson detection dogs found what they believe to be accelerants at the fires.
All four structures were vacant, and no injuries were reported.
The school was officially called East Side Primary, according to Seminole County's official website, and although it wasn't red, it became known as "The Little Red School House." The building was remodeled several times and later served as the home to Headstart, a soup kitchen and a center for displaced women. The school wasn't currently being used.
The four fires happened days after two blazes broke out at abandoned structures in Sanford, fire officials said. Two of the six fires happened on Palmetto Street, just blocks apart.
The Sanford Police Department said it will increase patrols in the area.
Watch Local 6 News and stay with ClickOrlando.com for more on this story.