PEBBLE BEACH, Calif. — The caddie for an amateur in the AT&T Pebble Beach Pro-Am collapsed on the 11th fairway Friday, and CPR was performed on him until an ambulance arrived to take him to the hospital.

In a tournament known for its easy vibe with celebrities and scenery, the final three hours at Pebble Beach took on a somber tone, particularly those on and around the 11th hole when the caddie fell over.

The PGA Tour did not release his name. Early reports were the caddie’s condition was improving. He was working for Pebble Beach businessman Geoff Couch, who did not return to finish the round.

“I turn around and he’s on the ground and I ran over to him and turned him over,” said country singer Lukas Nelson, the other amateur in the group. “And he didn’t have a lot of color in him. Luckily, there was a police officer on the sideline. He knew CPR so he came in and effectively saved his life.”

Gary Young, the PGA Tour’s chief referee, said a spectator began the CPR and an officer from Cal Fire took over from there.

PGA Tour players Beau Hossler and Max McGreevy, after consultation with PGA Tour officials, chose not to speak to reporters out of respect to the caddie’s family.

“It was especially jarring, the weirdest thing that can happen on a golf course,” Nelson said. “The good news is he’s at the moment doing better. From my perspective, it seemed like we lost him. And he’s still with us, so that’s important.”

After consulting with a PGA Tour rules official, Hossler and McGreevy marked their golf balls on the 11th hole and returned to the clubhouse. They were able to warm up and returned to the 11th hole after every group had come through to finish the round.

Harry Higgs was playing two groups behind and saw it all unfold. It brought back memories of Buffalo Bills safety Damar Hamlin, who suffered a cardiac arrest during a Monday Night Football game against Cincinnati and had to be resuscitated on the field.

“It had some shades of that,” Higgs said. “I was standing on the tee. They looked like they were 250 yards away, maybe even less, and they were hammering away CPR on the gentleman. It was weird.”

The groups behind, which included retired All-Pro receiver Larry Fitzgerald, played through as the tour figured out what the players wanted to do.

“We teed off on 11 and once I got up there and saw the group that the caddie was in, they were off to the side and they were obviously very emotional, hugging each other,” Higgs said. “I called a rules official over and just wanted to like, ‘Is this OK? I don’t want to be rude and keep going.’ It’s like golf doesn’t matter at all now, right?”

Nelson wasn’t sure he wanted to return, a feeling shared by others, except for getting good reports on the caddie’s improved condition.

“I think everybody on property knew what had happened and everybody was flat,” Higgs said. “There was no energy, no juice on any of the holes coming in. … Fortunately, we got some good news and kept going. I hope there’s more good news in the coming hours and days. Just very difficult and kind of a first — hopefully, a last.”

Kurt Kitayama made two late birdies to slide into the lead after two rounds. Kitayama is 9-under and holds a one-shot lead over Keith Mitchell, Brandon Wu, Joseph Bramlett and Hank Lebioda.

Two years ago, caddie Alberto Olguin collapsed on the ninth tee during a PGA Tour Latinoamerica event and died an hour later at a hosptial in Mexico.

In 2016, the first round of a Ladies European Tour event in Dubai was suspended when caddie Max Zechmann collapsed on the 13th fairway and died at a nearby hospital.

At the 2014 Madeira Island Open on the European Tour, caddie Ian MacGregor collapsed and died on the ninth hole while working for Alastair Forsyth. The tournament continued when Forsyth said that’s what his caddie would have wanted. One player, Peter Lawrie, withdrew out of respect.