A pastor and worshipers saw the Woodrow Baptist Church near Covington destroyed by fire Sunday morning.
The fire broke out just as the morning worship service was to begin, with some people already in the building.
All got out safely.
The call went out to the Covington Fire Department at 10:52 a.m., with fire departments from Itasca, Woodbury, Blum, Grandview, and Rio Vista soon responding to help.
One firefighter from Grandview received medical treatment at the scene for possible heat exhaustion, but was not hospitalized.
Most units cleared the scene by about 3:00 p.m. but a watch was continued for hotspots.
A post by Covington firefighters said that due to the volume of fire on arrival, it was determined that it would be a defensive attack on the fire.
The official cause of the fire remained under investigation Monday, but the pastor reported seeing first smoke, and then flames coming from an air conditioning unit, with the fire quickly spreading after that.