A series of earthquakes and aftershocks — some felt as far away as Wisconsin — shook the Texoma area this weekend, startling people more accustomed to tornadoes than temblors.

Early Saturday, a magnitude 4.7 earthquake affected areas from Texas to Missouri, followed by a 5.6 quake later that night — Oklahoma’s strongest in history — and more than 10 aftershocks.

Only one injury has been reported, but a 25-foot tower at St. Gregory’s University in Shawnee separated from an administration building and collapsed. Many Sooner State residents reported falling furniture and cracked walls, as well.

“It woke me out of a dead sleep,” Oklahoma City resident Noeh Morales said. “I felt the whole house shaking. I jumped and ran outside to see what was going on.”

US Geological Survey seismologist Paul Earle warned aftershocks could continue for days and even months.

While Oklahoma does not sit on a major fault, an unexplained sharp increase in the number of earthquakes there convinced researchers to install seismographs in the area last year. Local seismologist Austin Holland believes this weekend’s quakes came from movement along the complex and prominent Seminole Uplift fault structure.

Watch a local news report in the moments after the largest quake struck.