KENNETT SQUARE, Pa. - The fans who prayed daily for Barbaro and sent online messages of support never were able to get together to celebrate his recovery. This weekend, those fans will put away their keyboards to meet and honor his memory.

The Kentucky Derby-winning colt became a symbol of strength and courage before he was euthanized in January. Now, fans from around the world who sent cards, roses and fruit baskets finally will pay tribute to him Sunday on what would have been the horse’s fourth birthday.

“Just be warned,” said fan Sharon Crumb. “It’s going to be very emotional. I don’t think there’s going to be a dry eye.”

Crumb organized the “Celebration of Barbaro’s Life” on Sunday at Delaware Park, where Barbaro won his maiden race on Oct. 4, 2005. She’ll have some company. More than 500 FOBs — that’s Internet message board lingo for Fans of Barbaro — have committed to attending a day of racing, sharing stories and paying respects.

“I can’t let Barbaro go,” a choked-up Crumb said. “I won’t let Barbaro go.”

None of the FOBs will forget Barbaro, who was euthanized after complications from his gruesome breakdown at last year’s Preakness. Throughout nearly all his eight-month ordeal, those devoted fans met online at www.timwoolleyracing.com and found comfort in each other over their often-unexplainable and deeply felt bond to the champion horse.

“You didn’t feel alone,” Crumb said. “You felt like you were one big family. At the time, it was like medicine. A lot of people didn’t understand. Even my own family didn’t understand.”

Exercise rider Alex Brown created the chat room on trainer Tim Woolley’s Web site for racing fans. Brown is a rider at the Fair Hill Training Center in Elkton, Md., where Michael Matz trained Barbaro. After Barbaro’s injury, traffic spiked to more than 15,000 daily visits because of his updates on Barbaro’s condition.

Brown said his Web site still receives about 6,000 daily hits.

“When Barbaro was euthanized, I presumed that the Barbaro project would be over,” he said. “It wasn’t long after that I realized how wrong I was.”

The messages used to be about lighting candles, offering (sometimes odd) advice to the medical staff at the University of Pennsylvania’s New Bolton Center or telling Barbaro how proud they were of him — as if he could read. Now, the Web site serves as an organized platform for the FOBs to address more serious equine issues. They have raised about $250,000 and personally rescued about 580 horses, started fund drives for laminitis research and other equine diseases, and pressured lawmakers to pass anti-slaughter bills.

“It’s an incredible group,” Brown said. “A lot of people sort of presume and label them as wacky fanatics. But the reality is, this is a group of people that have done some amazing things.”

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The FOBs count this weekend’s celebration among them. The event at Delaware Park includes a “Fans of Barbaro” race in which 10 fans will be able to participate in winner’s circle activities, Barbaro highlight videos and a screening of the independent film, “The First Saturday in May.”

Other celebrations will be held around the country. Tampa Bay Downs in Florida will hold a birthday classic race, local FOBs are attending a race at Hollywood Park near Los Angeles, and the Shiloh Horse Rescue in Las Vegas is holding a weekend-long celebration.

Both Crumb and Brown are hopeful New Bolton staffers will attend, and Barbaro owners Roy and Gretchen Jackson are expected to make a brief appearance at Delaware Park.

“We went through a lot of tears together online,” Crumb said. “I just have this vision of us being together for one great big group hug. And I hope we heal. I don’t want people to say goodbye to Barbaro. I hope we become stronger.”