ST. FRANCOIS COUNTY, Mo. – Reports of a loud boom came in Tuesday evening from north St. Francois County to Iron County in rural Missouri.

According to reports from KFMO, the boom was heard and felt as the ground shook across the Parkland area. Locals suspected that the boom was an earthquake as Google Trends data showed the most searched term in Missouri was ‘Missouri earthquake today.’

Website FlightRadar24 later confirmed the F-15 went supersonic for six minutes. The aircraft took off from St. Louis Lambert Airport at 4:48 pm. It then went across St. Francois County to Ste. Genevieve from 5:17 p.m to 5:23 p.m. The plane then returned to St. Louis at 6:15 pm.

The U.S. Air Force defines a sonic boom as an impulsive noise similar to thunder. It’s caused by an object moving faster than sound at about 750 miles per hour at sea level. The aircraft travels through the atmosphere continuously producing air-pressure waves similar to the water waves caused by a ship’s bow.

A similar sonic boom was heard across mid-Missouri last week and was confirmed to be another Boeing F-15 breaking the sound barrier.