BANGKOK — A double-decker tour bus carrying students on a school trip to the beach crashed Friday into a truck in eastern Thailand, killing 15 people and injuring more than 30 others, police said.The fatalities included 13 children, between the ages of 10 and 15, and two teachers, said police Lt. Col. Anukarn Thammavijarn.The bus was carrying about 60 girls from a school in northeastern Nakhon Ratchasima city for a daytrip in the seaside town of Pattaya. As it drove along a downhill road in the early morning darkness, it lost control and slammed into an 18-wheeler truck that was in front of it, Anukarn said.After making impact, the bus spun around and slipped off the shoulder of the road. Pictures from the crash site in Prachinburi province, near their departure site, showed the windows had shattered on both levels of the bus.Police were searching for the driver, who fled the scene, and were investigating whether the brakes had failed or if the driver had dozed off at the wheel."We suspect there might have been a problem with the brakes, because the bus looked old," Anukarn said. "But we're not ruling out the possibility that the driver might have been asleep."Another double-decker bus carrying male students from the same school was following the girls' bus but not involved in the accident.Road accidents are common in Thailand, where safety standards are poor and road rules are rarely enforced. Last year, more than 8,600 people died in accidents on Thai roads.