Every generation thinks things are worse than they have ever been, that it couldn't get much worse, so we must be living in the last days and the end of the world must be soon. Various groups have thought the same at various points in history. Charlie Russel thought the same, he believed he was living in the last days and Christ was surely to return soon, bringing the end of the world in 1914. It was only when that didn't happen they decided that Christ had returned invisibly and they determined the end times had just started.
I was around when they believed Armageddon was going to come in 1975, that the generation alive in 1914 would not pass away before the end. People then also thought every negative news event signaled the end, the Vietnam war, the cold war, earthquakes. Everything confirmed their belief that it couldn't go on much longer. 1975 came and went and the Watchtower tried to pretend they hadn't led everyone to think it was going to be end of the world. Forty years later and they are still beating the same drum, they have redefined the meaning of the word generation, as if it means something different now. They learned nothing from their failed prophecies and still claim special knowledge of the end, despite the bible clearly stating that no man knows the day or the hour.
So what makes you think a terrorist attack that killed 127 people means the end? As horrific as it is, hardly compares to things that have happened in the past, the crusades, the bubonic plague, WWI and WWII, the Spanish influenza, the mass killing of six million Jews, the mass killing of people in Cambodia.
Don't get me wrong, mankind faces many challenges, but since God hasn't seen fit to step in before now, why would he at this point? What is so special and different about things right now that it means the end of the world?
