SIBLEY, Mo. (AP) — Parks officials say a grass fire damaged the Fort Osage National Historic Landmark in northwest Missouri.

The site will be closed indefinitely because of damage from the fire Sunday afternoon. The site near Sibley includes a replica of a fort that stood at the site in 1812.

The Jackson County parks department, which oversees the site, says fire damaged three buildings and a fence. The education center was damaged by smoke and also will be closed indefinitely.

The cause of the fire is under investigation.