West Salem, Ill. ? Bricks shook loose and fell from buildings. Walls cracked. Books tumbled off shelves.

A 5.2 magnitude earthquake centered near this southern Illinois town struck before dawn Friday, rocking skyscrapers in Chicago, 230 miles north of here, but doing little damage and seriously hurting no one.

It was the kind of tremor that might be ignored in earthquake-savvy California, but the temblor shook things up from Nebraska to Atlanta and rattled nerves in Milwaukee, Cincinnati and Louisville, Ky., where bricks toppled to the pavement.

“We thought it (the house) was falling on us, we really did,” said 85-year-old Anna Mae Williams, who was shaken awake at 4:37 a.m. in tiny West Salem, six miles from the epicenter.

Dozens of aftershocks followed, including one with a magnitude of 4.6.

The quake is believed to have involved an extension of the New Madrid fault, a network of deep cracks in the earth’s surface, the U.S. Geological Survey said. The fault is at the center of the nation’s most active seismic zone east of the Rockies, something that’s known to Midwest residents, even if they forget it now and then – the last severe earthquake in the region was a 5.0 magnitude quake in 2002.

Though nowhere close to the power of the nation’s most famous quakes – including the devastating temblor that hit San Francisco exactly 102 years ago Friday – it was enough to remind people of the risk that exists in the Midwest.

In 1811 and 1812, the New Madrid fault produced a series of earthquakes estimated at magnitude 7.0 or greater said to be felt as far away as Boston.