An investigation into a loud boom in the Janesville area appears to have no explanation so far. The Janesville Police Department reports receiving a handfull of calls from east-side residents about 9:30 a.m. Thursday. One suggestion is a sonic boom, but area airports report no military jets are operating in the area. Another theory being shared on Facebook guesses the noise and vibrations could have been the result of an ice or frost quake, which is caused by a sudden cracking in frozen soil. Residents who live several miles apart in Janesville reported on Facebook hearing a loud bang and feeling their homes shake. Several people from Milton and some from the town of Johnstown, Edgerton and other locations also reported hearing a loud noise.
