A driver towing a float in a Carnival parade accidentally ran over and killed his 16-year-old brother.Clay Michael Sayer was standing between Kain N. Sayer's pickup truck and the float behind it, talking to riders on the float during a brief stop around 5 p.m. Saturday, Trooper Scott Moreau said. The teen was pinned by the float when the truck started moving again, Moreau said.Kain Sayer, 21,...