Actress Keisha Knight Pulliam paid tribute to former The Cosby Show star Malcolm-Jamal Warner in an emotional post on her social media account on Sunday evening. The post featured Warner playing the guitar at a concert.

“A week ago I lost my big brother but I gained an angel… I love you… I miss you… We got our girls,” she said in the caption.

Warner tragically passed away on Sunday, July 20th, off the coast of Costa Rica due to a drowning incident. He had been swimming with his 8-year-old daughter when they began to struggle in the water. Surfers nearby quickly came to their aid, with one using a surfboard to bring Warner's daughter to safety. A volunteer lifeguard pulled Warner and another surfer to shore, where Warner received 45 minutes of CPR, according to police.

Authorities informed ABC News on Tuesday that an autopsy had been completed. The Forensic Pathology Department confirmed Warner’s cause of death as accidental drowning, described as asphyxiation by submersion.

Warner and Pulliam worked together on The Cosby Show. Warner played Theo Huxtable, the only son of Cliff and Claire Huxtable, in the sitcom. Pulliam played Rudy Huxtable, the youngest child of the Huxtable family and Theo's sister. Both characters were introduced in the pilot of the series “Theo's Economic Lesson,” which premiered in September 1984.

Pulliam is the latest The Cosby Show performer to pay tribute to Warner. Raven-Symoné, who portrayed Olivia, said in an Instagram post, “Words cannot describe the pain, sadness, and surprise that I feel with the recent loss of MJW. He was a big brother. He was a beacon. He was one of the most multifaceted, talented men…so gentle. He gave the best advice. He gave the best hugs, and his smile will always be a huge, bright, white smile in my head forever. I love you and I know you’re watching over all of us now.”