At least 13 people were killed early Sunday morning in a tour bus crash near Palm Springs, California, the Riverside County Coroner said. The bus struck a big rig just after 5 a.m. local time. At least 31 others, including the driver of the bus, were injured and taken to local hospitals. The bus was so badly mangled that firefighters took hours to remove bodies and injured victims. Officials said many of the dead were asleep at the time of impact. “The intrusion into the bus compartment is significant,” California Highway Patrol officer Stephanie Hamilton said. The bus was traveling from a casino in Salton City en route to Los Angeles. The National Transportation Safety Board said it was sending a team to the crash site to investigate.