DADE CITY — A 65-year-old Dade City woman died and another woman was seriously injured Wednesday when a Pasco County school bus ran a red light and rear-ended a Smart car and broadsided a Malibu, authorities said.The crash happened at 3:05 p.m. at the intersection of U.S. 301 and Morningside Drive. According to Dade City police, the bus struck the Smart car, which was stopped on U.S. 301 south, pushing it through the traffic signal and hitting the Malibu, said Officer Brian Uppercue. The Malibu was driven by Harian McDonald, who was traveling east on Morningside with her two teenage grandchildren. McDonald died at the scene. The Smart car driver, Patricia Austin, 61, was flown to Lakeland Regional Medical Center in serious condition, Uppercue said.The children in McDonald's car, a 14-year-old girl and a 13-year-old boy, were taken to Florida Hospital Zephyrhills to be checked for injuries.The bus driver, 57-year-old Bonita Mayle, and an aide, were both uninjured. No students were on the school bus.No charges had been filed, but the accident remained under investigation.