First, I am a tv reporter so Im telling this to you to perhaps look into. In the town of Long Prairie, MN on December 11th at 12:17PM a hugh boom was heard throughout business and streets on the south side of town (right infront of the auto value store) The explosion was so big that police closed off highway 71 for a short time and people got out of there cars. Witnesses say the sound and impact went through their bodies and was unbeleivable. One man described it as an exploding UFO, others say an earthquake or sonic boom. The problem with both of the later two theorys is that they're were no reported aircraft in the area and the USGS says it wasn't an earthquake.