PHILADELPHIA Sports is where we’re supposed to be able to go to get away from all this.

After September 2001 came October 2001. Baseball playoff games in New York City were transformed into cathartic events _ places to gather and share the pain while defiantly showing that our way of life was not going to be changed.

Not by terrorists, not by bombs, not ever.

Even Monday’s Boston Marathon was supposed to help heal a still-open wound. Organizers scheduled 26 seconds of silence before the start in honor of the 26 victims of the school shooting in Newtown, Conn. Parents of some of the Newtown victims were invited to sit in the VIP stands near the finish line.

The first bomb went off just across the way. Normalcy was transformed in a literal flash into chaos and confusion and agony.

As always, the best of us ran toward the blast site: police, paramedics, firefighters, ordinary civilians seeking to help rather than to flee. They are the ones the perpetrators can’t figure out.

The Boston Marathon is an insidiously perfect target for the kind of twisted mind that wants to create maximum shock value. What makes the event so special is what makes it so vulnerable.

It is a sporting event on the grand scale, like the Super Bowl or the Kentucky Derby or the Masters. But unlike all of those, where only the elite ever get to compete, a marathon includes both world-class athletes and regular folk. There are professionals looking to set world records and those on life journeys looking to prove something to themselves.

It is held out in the open, turning one of America’s great cities into the venue and the scene of the post-race celebration. That makes it great. It also makes it, by its nature, impossible to secure completely.

It is held on Patriots’ Day, a holiday in Massachusetts that will now forever be celebrated with a minor chord of sorrow in the mix.

But it will be celebrated. There will be a Boston Marathon in 2014, and the guess is here that record numbers will run the race. Because that is the flip side of all this brutality. It hurts. It maims. It kills. But it can never be allowed to win.

After Sept. 11, it was impossible to play NFL and major-league baseball games for those first few numb days. But then it was not just possible, it was necessary. There are a million ways to measure that life goes on, but nothing that engages so many of us simultaneously as our sports teams.

Of course, sports hasn’t always been sacrosanct. The Olympics will never be conducted without the shadow of the 1972 Munich massacre hovering. The Olympic Park bombing in Atlanta attempted but failed to derail the 1996 Summer Games.

After Sept. 11, 2001, there was a dread that our sports venues could become targets. The Super Bowl in New Orleans the following February was played under heavy security. Going on 12 years later, we are still accustomed to having our bags checked on the way into an arena or ballpark or stadium.

In 2004, the Knight Ridder newspapers required everyone assigned to cover the Athens Olympics to travel to Washington for special terrorism preparation training. We learned what to do if a bomb went off, if there was gas attack; the word “nuclear” was used. Those Games, played in range of the Middle East in the early going of the Iraq War, felt like the world’s largest bull’s-eye.

I remember covering the final competition, thinking it was the ideal target _ wide open, conducted all over an enormous city, impossible to secure.

The marathon.

Nothing happened, and we all took one more step toward returning to the day-to-day complacency we consider normalcy.

It is troubling but true. The more these things happen, the quicker we are to adjust and absorb and get back to our lives. We watch the live coverage, study the video, post our heartfelt shock and sorrow on Facebook and Twitter, and then we move on.

Within hours of the explosions and the shattering of lives and the death, locally the Phillies and Flyers and Sixers were all playing. They were all just a click of the remote from the relentless bad news from Boston.

Sports, after all, is where we go to get away from all this.