Accident de la route. Apparemment sa sœur avait sa ceinture, et n'a rien eu. lui n'avait pas de ceinture => coma.
Pour sa sortie du coma :
Citation :
In May 2010, Chi Cheng began showing significant signs of improvement, and was able to track individual people with his eyes, occasionally make worded responses, and slightly move his hands.
On February 7, 2012 it was reported that Cheng was in a partially conscious state, having the ability to move his legs on command; however, he was unable to move independently or speak in sentences