Malcolm-Jamal Warner, who rose to fame as the son on 1980s megahit The Cosby Show and had a prolific acting career that include series-regular slots on The Resident and Malcom & Eddie, died Sunday in a drowning accident in Costa Rica. He was 54.

Costa Rican National Police told ABC News that Warner’s official cause of death was asphyxia. Police said he died near Cocles, a beach in Limon, after being caught by a high current and was found Sunday afternoon.

The Associated Press reported that the local police initially reported that Warner “was rescued by people on the beach.” But first responders from Costa Rica’s Red Cross found him without vital signs, and he was taken to the morgue.

Warner — who later became a Grammy-winning recording act — had done a few guest shots on TV series including Matt Houston and Fame when he was cast on NBC’s The Cosby Show as Theo, son of Cliff and Clair Huxtable (Bill Cosby and Phylicia Rashad). The sitcom debuted in 1984 and was an out-of-the-box smash, finishing the 1984-85 season as the No. 3 show in primetime behind soaps Dynasty and Dallas. By the following TV year, it was No. 1 — where it remained for five consecutive seasons.

The Cosby Show help reinvigorate the sitcom genre and helped launch NBC to the top of the ratings heap, leading to its “Must See TV” era. Warner earned a 1986 Emmy nom for his role and would remain on the show for its full nearly 200-episode run from 1984-92.

“The Cosby Show was the first time on television you saw a Black family where the humor was not predicated upon how hard it is to be Black in America, or Black affectations and Black slang,” Warner said in a 2013 interview for the TV Academy Foundation. “Bill Cosby said the humor is in the truth. When you play the truth of the moment you’ll find the humor. That way you can make anything funny.”

He appeared in a couple of episodes of spinoff series A Different World, which starred Lisa Bonet — who played Denise Huxtable on Cosby Show — and aired for six seasons on NBC from 1987-93. Warner guested on Tour of Duty and The Fresh Prince of Bel-Air during his Cosby run and afterward toplined NBC’s short-lived Here and Now, exec produced by Cosby, which aired one season in 1992-93.

From there, Warner did guest roles on TV shows including Moloney, Touched by an Angel, Sliders and others before scoring his next starring gig. He and Eddie Griffin toplined Malcolm & Eddie, a UPN sitcom about two guys in Kansas City whose moms are best pals but have nothing else in common and become roommates. Early on, Malcolm often got sucked into Eddie’s get-rich-quick ploys. Then they won the lottery and bought their shabby apartment building. The show aired 89 episodes over four seasons from 1996-2000, skipping around the UPN schedule.

Warner also voiced The Producer on more than 40 episodes of PBS’ animated series The Magic School Bus, starring Lily Tomlin, from 1994-97.

He went on to star with Luke Perry in the Showtime drama series Jeremiah, which took place in a postapocalyptic world decimated by a virus. It aired about three dozen episodes from 2002-04. Next up was a series a leading role opposite Seinfeld alum Jason Alexander in Listen Up, in which they played mismatched hosts of a sports talk show on cable. Adapted from the writings of Tony Kornheiser, it aired on CBS for a single season in 2004-05.

Fast-forward a decade-plus, during which he did numerous gust shows on TV series and recurring as himself on Bryan Cranston’s Sneaky Pete, and Warner finally had another hit series.

Warner starred as AJ “The Raptor” Austin on the Fox medical drama The Resident, initially recurring in Season 1 in 2018-19 and becoming a regular for its final five season. He starred as a surgeon at Chastain Park Memorial Hospital opposite Matt Czuchry, Morris Chestnut, Manish Dayal and Shaunette Renée Wilson, who played his love interest. Chestnut was the cocky neurosurgeon Barrett Cain, who often would go toe-to-toe with Warner’s Raptor, a more down-to-earth, grounded character. Although they disagreed with one another plenty, there was a deep personal respect between them. When Wilson’s character Mina self deported back to her native Nigeria, AJ stayed behind caring for his ailing adoptive mother Carol Austin, played by Denise Dowse, who died in 2022.

Just before The Resident, was a series regular on ABC’s one-season drama Ten Days in the Valley, which starred The Closer alum Kyra Sedgwick and Adewale Akinnuoye-Agbaje. He also was a series regular on Lifetime’s 2008 Sherri Shepherd comedy Sherri and the 2011-15 BET multicam comedy Reed Between the Lines.

Warner also recurred on USA Network’s Suits as Julius Rowe — a role for which he auditioned four times. He was the prison psychologist of Mike Ross (Patrick J. Adams), who was incarcerated for practicing law without a license. The Julius character’s favorite TV show growing up was revealed to be The Cosby Show.

He also recurred as a police lieutenant on TNT’s Major Crimes and as Retta’s love interest on Girlfriends’ Guide to Divorce

Most recently, he recurred as Chief Inspector Bill Houston in 2025 episodes of the Fox drama Alert: Missing Persons Unit. He also played Al Cowlings on FX’s American Crime Story: O,J. Simpson and Angus T on American Horror Story: Freak Show, and recurred as Sticky, VP of The Grim Bastards, a Black motorcycle club in Kurt Sutter’s hit drama Sons of Anarchy.

Among his many guest-starring TV roles after the turn of the century were episodes of Grown-ish, The Irrational, The Wonder Years, Accused, Lethal Weapon, House of Lies, Key and Peele, Friends in Therapy and The Cleaner. He also had voice roles on Stripperella, The Chicken Squad, Puppy Dog Palms and Static Shock, among other toons.

Warner also had several directing credits, ranging from five on The Cosby Show and one on Fresh Prince of Bel-Air during the ’90s to more than a dozen on Malcolm & Eddie — he also was a producer on more than half of its episodes — some on All That and one on The Resident.

Along with his screen career, Warner also was a recording artist, winning a 2015 Best Traditional R&B Performance Grammy for “Jesus Children,” along with Robert Glasper Experiment featuring Lalah Hathaway, and earning a Best Spoken Word Poetry Album Grammy nom in 2023 for Hiding in Plain View.

Rosy Cordero contributed to this report.