The Comet and the Chicago Fire:
http://www.thunderbolts.info/tpod/2006/arch06/060206chicagofire.htm
Is there plausible evidence that a comet may have caused the Chicago fire and its regional counterparts? In 1985, Mel Waskin, who had earlier discovered Donnellys work, published a book, Mrs. OLearys Comet, suggesting that a comet did indeed spark the October 8th fires. More recently, Robert Wood, a physicist and aeronautical engineer formerly with Douglas Aircraft and McDonnell Douglas, gained attention from the Discovery Channel and other media for proposing the same idea.
The proponents of the cometary explanation cite many fascinating details confirmed by eye witness reports: the descent of fire from the heavens, a great tornado of fire rushing across the landscape and tearing buildings from their foundations, descending balls of fire, a rain of red dust, great explosions of wind accompanied by blasts of thunder, buildings exploding into flame where no fire was burning, and a good deal more. Some of the parallels with the later Tunguska event are impossible to miss.
One thing to note is many people died in the fire, which makes it very catastrophic.