WEST SALEM, Ill. -- Residents across the Midwest were awakened Friday by a 5.2 magnitude earthquake that rattled skyscrapers in Chicago's Loop and homes in Cincinnati but appeared to cause no major injuries or damage.

The quake just before 4:37 a.m. was centered six miles from West Salem, Ill., and 45 miles from Evansville, Ind. It was felt in such distant cities as Milwaukee, Des Moines, Iowa, and Atlanta, nearly 400 miles to the southeast.

"It...