NPS: Monuments at Gettysburg defaced with oil-based substance

GETTYSBURG, Pa. (WHTM) -- Authorities are investigating after someone recently defaced monuments at the Gettysburg National Military Park with oil-based substances. "While possibly intended as symbolic or ritualistic, the damage is real and lasting," the National Park Service explained. "Porous stone absorbs oil deeply, making stains nearly impossible to remove. Restoration takes months and costs [...]