Discovery.com re-states a claim made first in 1883 that the Chicago Fire may not have been started by Mrs. O'Leary's cow. The Great Chicago Fire claimed 300 lives and destroyed most of the downtown area in 1871. But does this cow deserve the blame? The Discovery Channel says no. Instead, Robert Wood, a retired physicist, claims it was a fragment from Biela's Comet which also induced blazes north of Chicago that burned millions of acres of farm and prairie lands. Wood speculates the main body of the comet crashed into Lake Michigan, with peripheral fragments causing the fires in Chicago, Wisconsin and Michigan.