The animosity between the Knicks and Boston Celtics is often palpable. There is plenty of history — and some of it nasty — in the long-time rivalry that will be renewed on Saturday when the two franchises meet in the NBA playoffs. But in the wake of the Boston Marathon bombings on Monday, the two sporting towns were linked by tragedy. No longer enemies, but friends. “It’s unfortunate,” Jason Kidd said. “It’s scary for something like that to happen.” Two bombs were set off near the finish line of the race killing at least three people and injuring more than 100. “It’s sickening,” Steve Novak said following the Knicks’ 106-95 loss to the Bobcats. “I heard there was an 8-year-old boy who died. I have a son. A lot of people have sons and daughters. It’s just sick sometimes what goes on. But you know that’s the world we live in. Those kinds of things happen. You can’t live in fear. You gotta continue to live your life, but it doesn’t change what happened to those people.” The NBA and local authorities will be on high alert in Boston when the Knicks and Celtics play Games 3 and 4 next week. The NBA’s immediate response was to cancel Boston’s final home game on Tuesday against the Pacers. The game will not be rescheduled. “The NBA expresses its sympathy to all those affected by the tragedy in Boston earlier today,” the league said in a statement. “It hits close to home for all of us,” Novak said. “You just hope that it stops. Obviously you can’t control it. More than anything, it breaks your heart that that kind of thing would go on in anyone’s head, especially at a sporting event.”