FREEPORT, Ill. (WTVO) — Freeport firefighters spent hours Saturday into Sunday working to put out a large structure fire after a grass fire spread to the building.

According to the Freeport Fire Department, crews were called to St. Paul Missionary Baptist Church around 4:16 p.m. on Saturday for a reported grass fire behind the church.

Firefighters said the fire had spread to a building at 525 East Stephenson Street.

Around 4:28, all off-duty Freeport firefighters were recalled to assist, and that was followed by a 5:06 p.m. call to surrounding area fire departments, including Lena, Dakota, Cedarville, and Rock City.

Three firefighters were treated for minor injuries at the scene, and crews remained at the location overnight and were put back into service again at 4:31 a.m. when the fire flared back up.

Officials said fire crews will be monitoring the building over the next several days.