The horrific scenes from the Boston Marathon bombings had a dreadful quality of déjà vu about them.

New Yorkers in particular remember the shock, horror and disbelief that we all felt on September 11 2001.

Incredibly, since that time and due to a combination of dedicated intelligence work, luck and terrorist incompetence, we have been spared the grisly scenes of death and destruction.

Yet there they were again on Monday, a very special day in the most Irish city in America, a special holiday commemorating the defeat of the British and in recent times the highlight of the Boston Marathon.

It is well-known that marathons are notoriously difficult to police. You have hundreds of thousands of spectators, thousands of runners, a festive atmosphere and people letting their guard down.

This also holds true for St. Patrick’s Day parades and July 4th celebrations. The ingredients for disaster are all there, with large crowds and a festive air, with security issues far below the radar.

Top New York cops have long feared an attack at the marathon in the city, and have identified it as one of the most vulnerable events of the year.

So we should not be surprised that the marathon in Boston was subject to a terrorist attack.

The injuries inflicted were horrific and a large number were on young children, no doubt brought to the marathon by their parents to take part in one of Boston’s most precious days.

Instead a cowardly and vicious attack took place on an American institution.

Right after the attack, as in 9/11, we saw the unquenchable spirit too.  Even though a bomb had just gone off hundreds rushed to help at the scene of the crime, not caring about their own safety in order to help the wounded.

It was thus after 9/11 too when the shocked survivors left the wreckage behind, and people poured form the buildings to give them support and help.

The bomb in Boston forces us to realize once again just how unsafe our modern world is. From school massacres to bombs at family events like a marathon, there are truly evil people on this earth who will stop at nothing to inflict pain and death on the most vulnerable and innocent.

Doubtless in the days and weeks ahead the reason for the bombing will become apparent, and who perpetrated the act will become known.

We do not know the identity at the time of writing, but the perpetrators will only have succeeded in strengthening people’s resolve that such heinous  acts will never succeed.

America will mourn those we have lost like we did at Newtown, on 9/11 and many other places and times of hurt and heartbreak.

But the resolve and the will to never give in to track down and punish, to make whole and get justice for the victims if that is at all possible  will live on as always.

Murder most foul was committed in Boston on April 15, but the spirit of America will continue on undaunted. It will take more than cowardly acts of killing children to break that.

The scene at the Boston Marathon surreal shocking and hard to come to terms with the community's new realityAP