Tragedy transcends even the most heated of sporting rivalries. That notion was on display Monday, when traditional rivals of the Patriots, Bruins, Celtics and Red Sox offered words support for the Boston community in the wake of the explosions that injured dozens near the finish line of the Boston Marathon. The Montreal Canadiens were among the teams to hold a moment of silence in honor of the victims, and a number of other clubs expressed their condolences via Twitter, including the Ottawa Senators, who were originally scheduled to play the Bruins on Monday night before the game was postponed.