Investigators with the State Fire Marshal's Office are looking into seven suspicious fires that happened within the last three weeks in Seminole County — the latest taking place Sunday.

As crews work to clean up the mess left behind by the fires, investigators put together signs to encourage people to come forward with any information they might have.

Shelley NeSmith lives near one of the recent fires. She said it's sad someone burnt down the Little Red Schoolhouse, which was built in 1883. City officials said it's the oldest school in Seminole County. 

A fire there was just one of the four fires that happened July 3. Crews were cleaning up all the debris Monday.

They said they will be at the site of the schoolhouse for a few days, but that's just one of the seven fires that have taken place since June 30.

The other fires took place at the following locations:

June 30
819 S. Palmetto Ave.
812 S. Sanford Ave.

July 3
6th Street and Palmetto Avenue
Little Red Schoolhouse, 519 S. Palmetto Ave.
West 20th Street and South Maple Avenue
500 Carriage Cove Way
Hester Avenue and County Road 427/Ronald Reagan Boulevard

July 20
2050 Pine Way

All seven fires happened in vacant buildings. They are being considered suspicious, the State Fire Marshal's Office said. It's unclear if all of the fires are connected, though.

"A lot of us are losing some sleep over it because we don't know how far the arsonist would go," NeSmith said.

Lisa Mosca, public information officer for Sanford, added: "It's really unfortunate when these historical buildings are burnt down. You can't go back. The history that goes along with that — the architecture. It's devastating.”

A possible suspect's car description or other video could soon be released, investigators said Monday.

For now, investigators are analyzing evidence they collected and are working to figure out if it's the same person involved in all seven fires. People who live nearby are just happy to see no one has been injured.

"I am not glad it happened to anyone, but I'm thankful it's abandoned places," NeSmith said.

Sanford officials said they are waiting to hear back from insurance adjusters to determine what to do with the land where the Little Red Schoolhouse was located.

Tipsters who provide investigators with information about who is behind the fires could be eligible for $1,000 in reward. Call CrimeLine at 800-423-TIPS (8477).