God Speed, John John.
Captain of my favorite Celtics teams, those of the early & mid 70's. Hondo, JoJo and Cowens were the Big 3 of the Celtics team that won two titles and very easily could have won four straight. Very fun team to watch - tough, selfless, competitive and ran opponents off the floor off outlet passes from Cowens & Silas. Also on those teams, Don Nelson, Charlie Scott, Hank Finkel, Steve Kuberski, Don Chaney, Paul Westphal. They won what to me is still the greatest NBA game ever played, 1976 Finals, Game 5 vs Pheonix, 3 OT. Unbelievable last 5 seconds of the second overtime including Hondo's running bank shot.
A quote from the story - "John Havlicek's defining traits as a player were his relentless hustle and wholehearted commitment to team over self".
Sounds like some lessons our current team could learn from.