Danny DeVito leads tributes for legendary Hollywood actor Kirk Douglas

Tributes are flowing in for iconic Hollywood star Kirk Douglas, who died on Thursday aged 103.

The sad news was confirmed by his son Michael Douglas, who shared his heartbreak in a touching Instagram post.

"To the world he was a legend, an actor from the golden age of movies who lived well into his golden years, a humanitarian whose commitment to justice and the causes he believed in set a standard for all of us to aspire to," Michael wrote alongside sweet images of Kirk with their family, including wife Catherine Zeta-Jones. 

"But to me and my brothers Joel and Peter he was simply Dad, to Catherine, a wonderful father-in-law, to his grandchildren and great grandchild their loving grandfather, and to his wife Anne, a wonderful husband.

"Kirk's life was well lived, and he leaves a legacy in film that will endure for generations to come, and a history as a renowned philanthropist who worked to aid the public and bring peace to the planet," he added.

"Let me end with the words I told him on his last birthday and which will always remain true. Dad- I love you so much and I am so proud to be your son."

Hollywood is also mourning the loss of the acting great, who was nominated for three Oscars throughout his six-decade long career. In 1996, Kirk was given an Honorary Oscar for his stellar 50-year contribution to motion pictures.

Members of the film industry have expressed their sorrow on social media, with Douglas family friend and actor Danny DeVito was one of the first to extend his condolences.

"Kirk Douglas. The inspirational Scalawag. 103 years on this earth. That's got a nice ring to it! Great hanging with you man," wrote DeVito, who has starred in numerous films opposite Michael Douglas, including The Jewel of the Nile and The War of the Roses. 

Actor William Shatner also reached out on Twitter. 

"Condolences to the family of Kirk Douglas. What an incredible icon he was in this industry!" the Star Trek legend tweeted.

Shatner's Star Trek co-star, George Takei, also shared some kind words about Kirk's charitable efforts. 

"Legendary actor Kirk Douglas has passed on today at the age of 103," Takei wrote.

"An Academy Award winning actor and recipient of the Presidential Medal of Freedom, Douglas was a champion for many just causes and lived a long and storied life. He was adored and beloved, and he shall be missed."

Director Rob Reiner remembered his friend and colleague, too.

"Kirk Douglas will always be an icon in the pantheon of Hollywood. He put himself on the line to break the blacklist. My love goes out to my friend Michael and the whole family," tweeted Reiner. 

British actor David Walliams took to Twitter, sharing a tribute to Kirk for his performance in the 1957 film Paths of Glory.

"Director Stanley Kubrick with actor Kirk Douglas on the set of 'Paths of Glory', one of the best (anti-) war movies ever made," tweeted Walliams. 

Meanwhile, Seinfeld star Jason Alexander said he was "heartbroken" about the news.

"Kirk Douglas was a friend and an absolute legend of a star and human. He got better with every passing day. So honored to have known him. My love to his family. We could use a true Spartacus." 

Here is how the rest of Hollywood has reacted the the tragic news: