Kalani David of Hawaii advances to the quarterfinals of the Pipe Invitational, the trials of the 2019 Billabong Pipe Masters, after winning Heat 3 of Round 1 at Pipeline on December 9, 2019, in Oahu, Hawaii. ED SLOANE/WSL VIA GETTY IMAGES

Former world junior surfing champion Kalani David died this weekend on a Costa Rican beach after suffering a seizure while in the sea practicing the sport in which he excelled, friends and authorities said. He was 24 years old.

Kalani David Feeney Barrientos, known internationally only by his first names, was born in Hawaii to a Costa Rican mother and had Wolff-Parkinson-White syndrome, a congenital heart disease that can cause paralysis and seizures.

However, his illness did not prevent him from succeeding in sports and he practiced both surfing and skateboarding. He won the Junior World Surfing title in Panama in 2012, in the Under-16 category, while competing for first place in the main skate circuits.

The young American died on Saturday morning in Playa Hermosa, Jacó, on the Pacific coast of Costa Rica, the Judicial Investigation Agency confirmed.

"He was surfing when he apparently suffered some kind of epileptic seizure and drowned," the entity said in a message to The Associated Press. "The death is still under investigation."

The filmmaker Peter King was one of the first to disclose his death through social media, while praising his fighting spirit.

"Oh friend, I love you Kalani! Only God knows the times of him. Life is not easy. Always fighting. Always learning," he said.

Various figures from the world of surfing echoed the news shortly after, such as 11-time world champion Kelly Slater.

"Kalani was one of the most talented surfers/skaters in the world," he said on social media.

His illness forced him to pause his sports career on several occasions but then he resumed it.

"He was constantly pushing his limits," Slater added. "My condolences to the great family and friends that Kalani had on every beach around the world."