Ken Howard, veteran character actor and president of the SAG-AFTRA actors' union, died Wednesday in Los Angeles, California. He was 71.
Howard's death was confirmed in a statement released by SAG-AFTRA, who said they were "deeply saddened" by his passing.
"Ken was an accomplished actor, author, teacher and unionist whose steady leadership as president of Screen Actors Guild positioned him to guide the union’s historic 2012 merger with American Federation of Television and Radio Artists," the statement continued.
PHOTOS: Stars We've Lost In Recent Years
His cause of death has not yet been announced.
Howard famously starred in the television series The White Shadow from 1978 to 1981. In the sports drama, Howard played Ken Reeves, a retired professional basketball player who takes a job as a coach at an underfunded inner-city high school.
Howard won a Primetime Emmy for his role in HBO's 2009 dramatization of the documentary Grey Gardens. That same month, the actor was elected president of the SAG.
More recently, he starred in a recurring role as cable company exec Hank Hooper on the NBC sitcom 30 Rock.
MORE: 9 ’30 Rock’ Predictions That Have Come True
Howard also enjoyed a successful theater career. He appeared in numerous Broadway productions over the years and won a Tony Award for Best Featured Actor in a Drama in 1970 for his performance in Child's Play.
Howard left an indelible mark in Hollywood, evidenced in the outpouring of condolences from stars throughout the industry.
George Clooney released a statement to ET, sharing his memory of the first time he met Howard as a up-and-coming performer:
"There’s a story about how a young actor met Ken on the Fox lot in 1983 and told him what a fan he was of The White Shadow. Ken asked that actor what he did and the young man said, 'well someday I hope to be lucky enough to work with you.' Then he told Ken he had an audition all the way across town at Paramount but he wasn’t going to make it because all he had was a bike. So Ken put his bike in the trunk of his car and dropped him off at Paramount. Then Ken just waved goodbye and said good luck, 'I hope we do get that chance to work together.'
"I didn’t get that audition, but I did get the chance to work with him years later. It was an honor. Today his obituary read that he was six foot six, but he was so much taller than that."
WATCH: See George Clooney, Brad Pitt, Julia Roberts & More Before They Were Famous
Howard's ex-wife, former advice columnist Margo Howard, paid tribute to her former husband in a series of messages on Twitter, writing, "My favorite ex-husband has died. He was a lovely guy. RIP Ken Howard."
She also shared a picture of Howard from his younger days, which she captioned, "This was the Ken Howard I married. Good times."
The two were married in 1977 and parted ways in 1991. The next year, Howard tied the knot with stunt woman Linda Fetters, and the two remained married until his death.
A number of other stars took to social media to share their memories of the actor, including Two and a Half Men star Jon Cryer, Will & Grace star Debra Messing, Frozen's Josh Gad, The Mindy Project's Ike Barinholtz and Howard's 30 Rock co-star John Lutz, among many others.