Magnitude 4.3 earthquake felt in Chicago

A rare moderate earthquake struck northern Illinois Wednesday morning, waking up residents in the Chicago area.

The 4.3 magnitude quake, centered 48 miles west of Chicago near the city of Sycamore, hit at 4 a.m. local time at a depth of about 3 miles, the USGS reported.

Geophysicist Amy Vaughn says the earthquake was "very widely felt" and the USGS phone lines were flooded with calls from residents asking about the shaking.

"It's mostly people who said 'we woke up and we thought we were going crazy,'" Vaughn said. "Mostly it's rattling people awake."

Kane County sheriff's spokesman Lt. Pat Gengler told the Associated Press dispatchers have been flooded with calls from startled residents, though no injuries or damage have been reported.

Gengler said several residential and business alarms were triggered, but deputies haven't been called for assistance.

Residents reported being shaken out of bed and finding books and tools scattered across the floor after falling from shelves.

Walter Mockus of St. Charles says, "The whole house shook. The chimes that hang were all ringing. It was so loud, I thought a plane had gone down."

On Twitter, user RosaMCabrera wrote: "Earthquake woke us! In ravenswood it was a second or so."

And Terryamerson said: "Thought it was the biggest snow plow ever that woke me up this morning. No it was 4.3 earthquake!"

Early reports suggest the quake was felt across three states: Illinois, Indiana and Wisconsin.