Powers Boothe was suffering from pancreatic cancer, which led to him dying from cardiopulmonary arrest ... this according to the death certificate obtained by TMZ.
The "Agents of S.H.I.E.L.D." and "Sin City" actor died in his sleep at his L.A. home a little more than 2 weeks ago. According to the document the immediate cause was a fatal heart attack, but Powers was also quietly battling cancer for at least 6 months.
The family held a private service in Texas for him. Booth was inducted into the Texas Film Hall of Fame in 2009.
He was 68.
RIP