SPARKS, Okla. (AP) ? One of the strongest earthquakes in state history rocked central Oklahoma late Saturday after a day of smaller quakes, a 5.6 magnitude temblor that rattled a college football stadium 50 miles away, shook buildings, caused cracks and was felt as far away as Tennessee, authorities said. Emergency authorities had no immediate reports of injuries or major damages. But one county’s sheriff’s office in the region said it was responding to calls and damages. The reports in the late-night hours were sketchy and the extent of damages remained uncertain early Sunday. The quake was one of several to rattle the state Saturday, including a magnitude 4.7 earthquake that shook the same area early Saturday.