In Game 5 of the 1976 Finals, Garfield Heard hit a 20-foot jumper from the top of the key as the horn went off to force the first triple-overtime in Finals history.

Part 3 of the nine-part “Celtics City” documentary on HBO premiered on Monday night with a focus on the 1970s Celtics amid a period of turmoil in Boston amid desegregation busing.