Jack Klugman -- who famously portrayed Oscar Madison on TV's "The Odd Couple" back in the '70s -- died yesterday at the age of 90.
According to Klugman's family -- the actor had been convalescing for a while, but died unexpectedly. Klugman's cause of death has not yet been determined.
But Klugman was tough as nails -- in fact, he battled throat cancer back in the '80s and lost his voice, but later trained himself to speak again. Pretty bad ass.
As an actor, Klugman appeared in some iconic movies and TV shows -- including "12 Angry Men" and the 1959 musical "Gypsy. He also appeared in several episodes of "The Twilight Zone" and starred in "Quincy, M.E."
Klugman is survived by his two sons.
tmz