Malcolm-Jamal Warner, best known for portraying Theo Huxtable on the 1980s sitcom “The Cosby Show,” has died at the age of 54. Costa Rica’s Judicial Investigation Department said the American actor drowned Sunday afternoon while swimming off Playa Cocles on the Caribbean coast, where he was vacationing with family. First responders from the Costa Rican Red Cross found him without vital signs and pronounced him dead at the scene. An autopsy completed on Tuesday listed the cause of death as accidental asphyxiation by submersion. Emergency crews also treated a 35-year-old man involved in the same incident, who was transported to a local clinic in critical condition, according to Red Cross officials. Local volunteer lifeguards said no guards were on duty at the beach at the time because of limited resources, describing the area as prone to strong rip currents. Warner’s eight-season run on “The Cosby Show” earned him a 1986 Primetime Emmy nomination for supporting actor. He later appeared in series including “Malcolm & Eddie,” “The Resident” and “Alert: Missing Persons Unit,” and won a Grammy in 2015 for best traditional R&B performance. Tributes have followed from Fox Entertainment, the NAACP and former co-stars, with Bill Cosby calling Warner’s death a personal loss. Warner is survived by his wife and a daughter.