"We keep running."

Reporter Nancy Chen tweets this photograph of writing on the sidewalk outside the home of Martin Richard, the 8-yo who was killed in the Boston Marathon bombing yesterday.

For every person who runs marathons, writes Jeb Golinkin in The Week, the word "Boston" has a special meaning. And much more so today. A number of marathon runners I know posted this article on social media yesterday, and while I don't have what it takes to do what they do, I can see why the essay resonates:

I do not possess the requisite skill to express what I am feeling right now. But I know this: A marathon is ultimately a test of toughness and resolve. Those who run them typically do so to prove to themselves that they can fight through great adversity and still prevail. This nation's history shares the same spirit that the marathon showcases, and as we always have, we will prevail. We will mourn our dead, help our wounded, bring the criminals who committed this heinous act to justice. America will not quit. It will not stop running. And the Boston Marathon will not go away.

Also in The Week, a good rundown of four theories on who did it. TL;DR: Islamist jihadists, right-wing white American militia types, the gubmint (false flag), lone nutjob. That pretty much covers it, although human depravity always exceeds what we are capable of coming up with using logic.

Previously: "Boston marathon bombed — two explosions, many injured, at least three dead."