It was the “5.2 magnitude earthquake” that shook and awoke people across the Chicago area yesterday morning, reported the U.S. Geological Survey. The epicenter of the earthquake was the Downstate Illinois.

According to the U.S. Geological Survey, the earthquake, which was initially estimated of the magnitude 5.4, but was later measured 5.2 on the Richter Scale, struck at 4:36 a.m. near the town of West Salem, Illinois, about 60 miles northwest of Evansville, Indiana. The tremors could be felt in downtown Chicago at the Tribune Tower, 435 N. Michigan Ave., for about 20 seconds beginning around 4:40 a.m. The biggest on record, was 5.4, which occurred in 1968.

The Illinois State authorities reported that there were no immediate reports of injuries or significant damage. The Illinois State Police were investigating whether the earthquake was responsible for leaving a "metal rod" sticking up out of the pavement on the Edens Expressway near Dempster Street. Chicago Fire Department Chief Joe Roccasalva said, the tremors caused a "huge spike in calls" to the city's 911 center, but fire crews had not responded to any emergencies related to the incident. He said, "It's mostly people calling to say things were moving on their shelves, that the earth was moving."