On June 5, 2009 (May 13, 2009 in the lunar calendar), 27 people died and 74 injured in a deliberate fire incident on a "June 5" bus in Chengdu, Sichuan. At about 8 o'clock on June 5, 2009, a No. 9 bus burst into flames at the Sichuan-Shaanxi overpass on the Third Ring Road in Chengdu City, Sichuan Province, killing 27 passengers and injuring 74 others. After the incident, the public security organs went all out to carry out a large number of surveys, inspections, investigation experiments, and visits and investigations. After a lot of hard and meticulous work, the Chengdu bus burning incident has been determined to be a criminal case of intentional arson. Zhang Yunliang, who was burned to death in the rear of the car, is the criminal suspect in the intentional arson case. Police said that 62-year-old Zhang Yunliang was from Suzhou City, Jiangsu Province and temporarily lived in Chengdu City before the incident. He was originally from Jiangsu Province and was addicted to gambling and had not done a proper job for a long time. Since arriving in Chengdu in 2006, he has no legitimate employment, and his main source of income is financial support from his daughter. In 2009, his daughter reduced the living expenses he gave him because of her prostitution and gambling. Zhang Yunliang repeatedly threatened to commit suicide and asked his family for money, and showed a sense of pessimism. On June 4, during a phone call with his daughter, he said,"I won't have it tomorrow" and "different from the way others died". On June 9, his family received a suicide note sent by Zhang Yunliang from Chengdu before the murder. After investigation, at about 7:40 on June 5, Zhang Yunliang carried a plastic bucket filled with gasoline and got on the No. 9 bus at the departure station of Tianhui Town. A passenger confirmed that when the vehicle was driving from north to south into the city to the Sichuan-Shaanxi overpass on the Third Ring Road, Zhang Yunliang poured the gasoline he carried in the vehicle and ignited it, causing the vehicle to burn. According to on-site inspections, there were traces of gasoline flowing in the direction of the front on the floor where Zhang Yunliang was sitting. This area was the most serious burning level, and the expert group identified it as an ignition area. Through on-site inspections, it was confirmed that only Zhang Yunliang's body was in the central area where the vehicle caught fire, and a lighter wind shield was extracted next to his body. The posture and orientation of the body fell to the ground showed that Zhang had no intention of actively escaping after the fire.