Keshia Knight Pulliam is mourning her Cosby Show co-star Malcolm-Jamal Warner . A week after Warner’s tragic drowning death at age 54, Pulliam took to Instagram to express her grief.

The actor made famous by playing Theo Huxtable in "The Cosby Show" died this weekend in an accident in Costa Rica.

Beyoncé shared a touching tribute honoring Malcolm-Jamal Warner, following his tragic drowning on a beach in Costa Rica.

Journalist and professor Candace Kelley, who hosted the Not All Hood (NAH) podcast with the late 'Cosby Show' actor, opens up to PEOPLE about her memories of Malcolm-Jamal Warner, calling him a man who was hilarious,