The Georgia Bureau of Investigation said “unknown individuals” detonated an explosive device around 4 a.m., destroying a large portion of the Georgia Guidestones. The structure, which has been dubbed “America’s Stonehenge,” originally consisted of four 19-foot granite slabs, a center stone and a smaller block capping the top. Video footage released by law enforcement shows a car leaving the scene shortly after the blast, although the GBI did not specify whether the driver was connected to the incident. Later in the day, authorities demolished the whole monument, citing safety reasons.