Complex sentence: Gann would endure several more tragedies in his personal life, including the death of his eldest son in 1973; while working on an oil tanker in the Gulf of Alaska, George was swept overboard in a storm.
Split into simpler sentences: Gann would endure several more tragedies in his personal life, including the death of his eldest son in 1973. While working on an oil tanker in the Gulf of Alaska, George was swept overboard in a storm.