A fire alarm was triggered at TD Garden in the aftermath of the New York Knicks’ 91-90 playoff victory over the Boston Celtics on Wednesday night, causing a brief evacuation.

The Celtics’ 108-105 overtime loss Monday night — a game the hosts led by 20 points with less than six minutes remaining in the third quarter — was the kind of harsh lesson in basketball hubris that these guys, collectors of the 18th banner, should be beyond having to learn.