In the wake of Charles Durning's and Jack Klugman's death, a number of celebrities took to Twitter to pay their respects for the two Hollywood great actors. Among the mourners were fellow celebrities Whoopi Goldberg and Jon Favreau.

Whoopi re-tweeted a short note that read, "Charles Durning RIP wonderful actor." One day earlier, the "Sister Act" actress wrote, "R.I.P Jack Klugman, Oscar, Quincy a man whose career spanned almost 50 years. I first saw him on the Twilight Zone. Cool guy wonderful actor."

Jon re-tweeted a post by Seth Meyers, "RIP Charles Durning. Amazing obit in the NYT. Was in the first wave of troops to land on D-Day," with a link to an obituary of the late actor. The "Iron Man" star previously remembered Jack as writing, "You made my whole family laugh together."

Charles was also saluted by Denis Leary, who starred opposite his on-screen son in his last TV series "Rescue Me". "Charlie Durning RIP. Hero of WW2. Fighter. Dancer. My fake Rescue Me Dad," the Tommy Gavin depicter wrote about his on-screen father.

"Family Guy" creator Seth MacFarlane re-tweeted a fan's message that read, "First Phyllis Diller, now RIP Charles Durning. Sad day for the #FamilyGuy company // Peter Griffin misses his mom & dad." Charles voiced recurring character Francis Griffin, while Phyllis who died last summer voiced his on-screen wife Thelma.

Adam Shankman and Kirstie Alley also shared their loving memories about the late stars. The former posted, "Rest in loving peace #jackklugman and #charlesdurning: 2 of the greatest character men who ever graced us w/their talent. Sleep sweet guys." The latter wrote, "My dear friend you will be missed #charlesdurning One of the finest actors in the world."

Meanwhile, "New Girl" actor Max Greenfield recalled his experience of working with Jack, who's best known for his role as the sloppy Oscar Madison. "I worked with Jack Klugman several years ago. He was a wonderful man and supremely talented actor. He will be missed," he noted.

Dan Schneider, the mastermind behind Nickelodeon's TV shows such as "iCarly", called Jack as one of his inspirations in another solemn message. "So sorry to hear that Jack Klugman passed away. I learned a lot, watching him on television," he wrote.

Both Charles and Jack died of natural causes on Monday, December 24.