Terrible news. Not that it matters, but anyone know what his religion was, if any? He almost always played kung fu and martial artist type roles, but no indication if was in any way interested in Eastern religions. The wikipedia page on him does not say, but mentions:
Carradine produced and starred in several exercise videos teaching the martial arts of Tai chi and Qi Gong. Carradine actually had no knowledge of martial arts prior to starring in the series Kung Fu, but developed an interest in it after this experience and became an avid practitioner.
He was in Bangkok, too bad he just didn't ordain and try and figure something out, with his problems.