If you saw the video of yesterday's blasts, you saw the runner above collapse as though he'd been hit with shrapnel. Thankfully, it was just the force of the blast that knocked him off his feet. He suffered only a skinned knee. . All of my friends survived the marathon with no serious injuries. Unfortunately, that means someone else's friends didn't. . On my way to work in Boston this morning, Reservists in full combat uniform were keeping an eye on things in the subway station. Later in the morning, my colleagues and I heard barking dogs, looked out our office window and saw three SUVs from the K-9 squad getting ready to patrol the area. . We can't help but obsess about what happened yesterday. Don't get me wrong, we feel pretty safe. We just can't stop thinking, talking, texting and emailing about what happened. . I honest-to-God can't imagine how the people of New York and Oklahoma City managed to function in the days following their much bigger massacres.