Thunderstorms may have caused crop circles Meteorologists are investigating whether fierce thunderstorms caused crop circles in parts of Canada. Environment Canada officials say swirling vortices of air or downbursts may be behind circles in fields in New Brunswick and Prince Edward Island. The severe weather on Thursday and Friday also uprooted hundreds of trees and damaged a number of buildings. Canada.com reports that Environment Canada's Mike Campbell said: "What we believe is a lot of air had rushed out of the thunderstorm and when it hit the ground it swirled around. It just whipped up the crops and flattened them...