Complex sentence: Both Costello and his tag team partner Heffernan died before Kangaroos were honored as the first tag team to ever be inducted into the Professional Wrestling Hall of Fame in 2003, which started a tradition of inducting a new team every year.
Split into simpler sentences: Both Costello and his tag team partner Heffernan passed away, before the team was honored by being the first tag team inducted in the Professional Wrestling Hall of Fame in 2003. The induction of The Fabulous Kangaroos started a tradition of inducting a new team every year.