David Seigfried was walking his dog when he slipped in a clear, squishy, gel-like substance that nobody has been able to explain. It's on the roof of his Forest Hills home, and 5 feet around in the ... more 
David Seigfried was walking his dog when he slipped in a clear, squishy, gel-like substance that nobody has been able to explain. It's on the roof of his Forest Hills home, and 5 feet around in the yard in all directions. less 
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WTAE - Pittsburgh Videos
Tue, May 8, 2012 11:44 PM EDT