Clarence Gilyard Jr., a veteran scene-stealer who appeared in the ’80s blockbusters “Top Gun” and “Die Hard,” has passed away following a battle with an unknown illness. He was 66 years old.

Clarence Gilyard, the actor best known for playing computer hacker Theo in “Die Hard” and naval flight officer Marcus “Sundown” Williams in “Top Gun,” has died at the age of 66.

In the '80s, "Die Hard" seemed impossible to cast, with Hollywood heavy hitters like Schwarzenegger, Clint Eastwood, Richard Gere and others passing on the role as NYPD Det. McClane.