A tour bus skidded from an off-ramp of the 10 Freeway in Baldwin Park into a drainage ditch Monday morning, leaving 13 people injured, authorities said. The crash happened around 4:30 a.m. when the bus driver lost control as the vehicle exited the freeway, according to the California Highway Patrol. The vehicle then slammed into a pole and landed on its side, the CHP said. Officials said 39 people were on the bus, including the driver.