The 5.6.-magnitude temblor near Pawnee, Oklahoma, is one of thousands to strike the state in the last few years.
State and federal scientists say the swarm of earthquakes in central and **rth-central Oklahoma is connected to the area's oil and gas companies, which are pumping copious amounts of drilling wastewater into underground disposal wells.
Oklahoma's Gov. Mary Fallin this weekend declared a state of emergency for Pawnee County after the earthquake struck on Sept. 3 near Pawnee, a city of about 2,200 people. Read more...