Cheng was seriously injured in an automobile crash in Santa Clara, California, on November 4, 2008. Cheng was traveling with his sister, Mae, when their vehicle flipped three times after hitting another car going 60 mph. Cheng, who was in the passenger seat, was not wearing a seat belt and was ejected from the vehicle. Mae was wearing a seatbelt and sustained minor injuries. She attended to Cheng, holding his head until two off-duty paramedics rendered aid. They were able to insert a tube into Cheng's throat to help him breathe until the ambulance arrived, an action that doctors later said helped him survive. The crash left Cheng in a coma.