Bill Cosby is mourning the death of his longtime co-star and on-screen son, Malcolm-Jamal Warner, who died at the age of 54 while on a family vacation in Costa Rica.

More details have emerged about the tragic death of Malcolm-Jamal Warner.

Lifeguard instructor Mike Geist, who is also the vice president of Caribbean Guard, explained to Us Weekly on Tuesday, July 22, exactly what transpired that tragic afternoon.