By MATT WIXON When I was in elementary school, Sparky the fire dog would visit occasionally. He was 6 feet tall, bumped into desks, and, in a strange coincidence, wore the same shoes as our P.E. teacher. But the kids at Horizon Elementary, home of the fightin' Panthers and the occasional lice outbreak, took Sparky seriously. After all, he and his fellow firefighters brought along a message about fire. How quickly it could spread, how destructive it could be, and how a fire could happen at our house, even when we were sleeping. Yes, Sparky and company pretty much scared the bejesus out of us. Take, for example, the "stop, drop and roll" thing. It was fun to practice, because rolling on the ground would turn into rolling into each other, which would turn into somebody knocking over a desk. That would turn into a teacher screaming at us and Sparky raising his paws to his cheeks -- creating the international mute-mascot hand signal for "Oh my!" But then we would rea