There's a picture on the front page of Tuesday's Boston Globe - in the background of the shot, someone is bent over an injured spectator, administering care.
I looked closely at the picture and realized that someone was my brother Jack.
Jack has been volunteering as an athletic trainer at the Boston Marathon for several years, and he was stationed at the finish line only yards from the scene of the first explosion.
On the footage that ran over and over that first night, you can see Jack, just seconds after the blast occurred, running toward - not away - from the blast.
Jack would say that he only did what so many other first responders did, what so many other Americans, Bostonians, emergency and medical personnel, soldiers, police, nurses and other caregivers did.
He ran over to help out - not thinking about his own safety and never a thought about whether the victims were runners or spectators, white or black, old or young, Democrats or Republicans.
The whole red state/blue state thing doesn't mean much to Jack anyway, and I don't think it meant anything to anybody else watching that horror on Monday afternoon.
Thomas Jefferson wrote once that, "It's part of the American character to consider nothing as desperate."
He wrote those words at a time when Boston was a city of heroes for completely different reasons - for standing up to an oppressor, for hanging tough as the very first "guerilla" fighters in modern military history.
But today, Boston is a city of heroes again, only this time not warriors per se, but random Good Samaritans.
Speaking of Good Samaritans, I had a conversation with Fred Rogers - late of Mister Rogers' Neighborhood of children's TV fame - toward the end of his life.
I took the opportunity to thank him for all the good ideas he shared with our three (then) little boys, and we talked about his influence on the lives of our children and the children of millions of other parents.
In his typically humble way, Mr. Rogers turned the conversation back to me. We had moved on to the topic of violence on TV and its effect on children.
He asked about my experiences in Belfast, Northern Ireland back in the 1970s and '80s, where I had seen some horrific violence not at all unlike what we just witnessed in Boston - only there the weapon of choice was "sugar and jelly" (gelignite) bombs, designed to literally stick to their victims.
I asked him what could be his message for children, especially when those sorts of scenes played themselves out over and over in our 24/7 news and media environment.
And he had a very simple answer - one which he credited to his own mother.
He said that whenever they encountered violence on the nightly news, his mother admonished them to "Look for the helpers."
Look for the helpers, indeed. I think that's good advice for today as well. Look for the helpers. And thank them, early and often.
Thank you, Jack.
Tom Foley is president of Mount Aloysius College. His brother Jack is assistant athletic director and director of sports medicine at Lehigh University.