'Home Alone' Dad John Heard Died From Heart Attack

John Heard -- who played the dad in "Home Alone" -- died in a California hotel room after suffering a heart attack brought on by heart disease, officials tell TMZ.

The 71-year-old was found in a hotel in Palo Alto, CA on July 21.

The Santa Clara County Medical Exmainer's Office conducted an autopsy and found Heard died of a "sudden cardiac death due to atheroscerotic and hypertensive heart disease."

Heard had undergone minor back surgery 2 days before his death at Stanford Medical Center (a short distance away) and was staying in that hotel while he recovered.

But officials say Heard's "recent back surgery did NOT play a role in his death."

As for toxicology, the results have not been made public.