They're devastated, shocked, even "gutted."
Generations of golf's best players, fans and writers took to Twitter on Sunday night to hail the accomplishments and influence of the sport's icon, Arnold Palmer, who died Sunday at age 87.
They shared their shock, admiration and memories in a flurry of tweets to honor "The King."
Fellow golf legend, longtime rival and "best friend" Jack Nicklaus said Palmer "transcended the game of golf."
"He was more than a golfer or even great golfer. He was an icon. He was a legend," Nicklaus said in a statement shared to Twitter. "Arnold was someone who was a pioneer in his sport. He took the game from one level to a higher level, virtually by himself."
"Thanks Arnold for your friendship, counsel and a lot of laughs," Tiger Woods said on Twitter and Instagram. "Your philanthropy and humility are part of your legend. It's hard to imagine golf without you or anyone more important to the game than the King."
"I will never forget the bear hug in front of the clubhouse at Augusta," tweeted Ricky Fowler, the world's ninth-ranked golfer. "I love you as did everyone."
Many, like 26th-ranked golfer Emiliano Grillo, noted how Palmer touched so many lives.
"Gutted" is how golfer Colt Knost described himself upon learning the news.
One Washington, D.C., sports writer reminded us that no one will ever be as cool.
Brandt Snedeker called knowing Palmer "one of the highlights of my life."
And a noted golfer named Barack Obama tweeted a picture of his putting in the Oval Office as Palmer looked on.
"Here's to The King who was as extraordinary on the links as he was generous to others," the president said. "Thanks for the memories, Arnold."