Surely the irony of terrorism is that it brings us closer together. These things offer a shared experience where everyone finds their greater humanity in being there for each other. These moments do the opposite of what terror is intended to do.
Maybe that comes from the shock of the reality that what we think does not happen does happen. It proves in some way that we are still live with optimism, that we are still more generous than selfish and when these things happen we notice again that better part of ourselves and our humanity, and it is attractive.
Maybe that in turn comes from the sympathy we feel for those who are caught up in this, those who have died and injured who remain unnamed as yet and for whom we feel so helpless. Empathising rather than sympathising is a sign again of our greater humanity where we can share pain and shock regardless of culture and religion because we are universally human first and only second a particular religion or culture.
So the irony is we feel closer to each, even a pride in what we have seen of our humanity today unless we are so angry or selfish that we can't see beyond the masks that we chose to construct. We hurt for those who have been injured and killed because it hurt our humanity that comes to the surface again when it is under threat but the very fact that it does so proves it is still far stronger than fear.