A rumble that was felt throughout the city of Mankato Tuesday morning had many residents wondering if their town was just victim to an earthquake.
Officials say the ground shaking was due to a controlled blast at Jefferson Quarry. But the incident remains under investigation. So what the heck?

Mankato residents were trembling as they posted about what they believed might have been an earthquake Tuesday morning. According to social media reports, the shaking happened at about 11 a.m.
The U.S. Geological Survey (USGS) said the blast was so strong, they measured it at an earthquake magnitude of 2.8.
Just felt the earthquake in Mankato! Thought I was getting dizzy but my office was actually shaking ?!
— Mandy Weister (@MandyWubben) April 25, 2017
Our offices were just rattled in Downtown Mankato. Early reports are saying a potential earthquake or explosion nearby. Did you feel it?
— C21 Atwood Realty (@atwoodrealty) April 25, 2017
Earthquake in Minnesota. 11:02 AM CST in Mankato 4.27.17, noticeable subtle shaking for less that 5 seconds. #Science #MnSTA
— Eric Koser (@EKphys) April 25, 2017
No joke. Mankato just had an earthquake and we evacuated the office.
— Taylor Marie (@taylor_marie_y) April 25, 2017
Before and after 1906 San Francisco earthquake and 2017 Mankato, MN earthquake. pic.twitter.com/k258wh6xxj
— Trenton Dumitrache (@TrentonDumit) April 25, 2017
The Mankato Free Press reports the local dispatcher from Blue Earth County said they were overwhelmed with 911 calls reporting the rumble. Other residents told the local paper they felt as though their house was about to collapse, so they fled outside.
A press release from the city states, “Today at 11:04 a.m. a controlled blast was conducted in the quarry at 900 Cleveland Avenue. Afterwards, a vibration was felt through most of the city. It is suspected that due to weather, overpressure may have caused a ‘pressure wave.”
City officials say no injuries were reported or damages to any structures in the city. However, all blasts have been suspended until further notice. According to reports, it was a scheduled, controlled explosion.
Minnesota is rated by USGS as one of the very least likely states in the nation to be hit by an earthquake.