Two motorcycle riders died Sunday afternoon in a crash on a popular, twisting route up Palomar Mountain, according to a Cal Fire spokesperson. The crash occurred around 1:20 p.m. near mile marker 10.6 on East Grade Road, said Cal Fire Capt. Mike Cornette. The riders died before they could be taken to a hospital. Two tow trucks were called to take away their vehicles, he said. The California Highway Patrol is investigating the crash. According to a CHP online incident log, the road was closed in both directions for the investigation. It appeared only the two motorcycles were involved in the crash.