A Waterloo man and his dog made a harrowing escape from the clutches of a vicious black bear Thursday while portaging near Wawa, Ont. Tom Tilley, 55, killed the nearly 200-pound bear by jumping on its back and stabbing the aggressive animal with a six-inch hunting knife after his dog alerted him and distracted the bear. "Love is a very powerful emotion and my thought right away was, 'You're not going to kill my dog,' " Tilley said yesterday. "I really consider my dog a hero. Without that first warning I would have had the bear clamping down on my...