The athletes and spectators running into the chaos serve as a reminder that we are, all of us, in the humanity business together. Their brave trajectory tells us, to paraphrase Philip Larkin's poem, that what survives of us is love.
Our country's citizens have already given up greeting airline passengers at the gate in the name of safety, endured long lines entering football stadiums for thorough body searches, and tolerate metal detectors in government buildings to ensure safety.
I remember hearing explosions the night before my eighth birthday -- not the kind of explosions that happened this week, but the other kind; the good kind. I crawled out of my sleeping bag and went to look out the window, and I saw a sky filled with fireworks.