Police: Driver in deadly school bus crash was speeding

CHATTANOOGA, Tenn. -- The 24-year-old driver in a Tennessee school bus crash that killed six children was speeding about 20 miles per hour over the 30 mile-per-hour limit, police testified Thursday, drawing tears from their families in court.Johnthony Walker also was using a cellphone in the bus before the crash, Chattanooga traffic Officer Joe Warren said.He estimated that Walker was driving between 48 and 52 mph and never hit the brake. He knew "right off the bat" he was dealing with a speedin