In April of 2004, I sat on the grass at the high school in Hopkinton, waiting for the start of the Boston Marathon. Temperatures were high—86 degrees at start time and all of my training runs in Montana had been at 40 degrees or less. I was worried. So was everyone else.

After the start, I settled into a slow pace, determined to save energy and make it to the finish. By mile 6, I was feeling woozy and slowed even more. I desperately wanted to see the screaming fans along the route and the crowds gathered near the finish line. And I wanted to go home with a Boston finisher's medal.

I had qualified for the Boston Marathon by running 3 hours, 25 minutes at the Montana Marathon. On Boston race day, I finished in 4 hours, 18 minutes, almost an hour longer, but the slow pace paid off with the joy of running down Boylston Street, hearing the noise of the crowd, crossing the finish line and collecting my medal. It was pure joy.

Beyond the finish line, the evidence of the hot day was everywhere. Over 1,000 people were taken to the medical tent. Exhausted runners were flopped down in the street and anywhere there was an open space. I made a comment when I got home that Copley Square looked like a war zone.

Ironic and sad now, because in 2013, that is exactly what the finish line and Copley Square became when bombers attacked one of the greatest of American institutions. Like the rest of the country, I watched the news reels in horror. How could this happen? Patriot's Day is a day of celebration, of baseball, basketball, hockey, and running in a setting filled with national history. I looked at the pictures of wounded runners and spectators. I tried to match them with the images in my head. My joy and their fear, sadness, and pain.

I was haunted by those photos for days. I had difficulty teaching, so I discussed this with each class of students. It was too unreal and too unbelievable.

I grieved for those who were dead or injured. I felt sympathy for those were emotionally wounded from the horror of the experience. I identified with those who had dreamed of running the Boston Marathon, had trained for months or years, had finally qualified, and made the journey to participate in the oldest, continuous sporting event in the country. For many, qualifying for Boston is a once-in-a-lifetime chance. They were living in a dream when it became a nightmare and thousands who were so close to finishing a lifetime goal were denied that moment.

I think back to my experience at the finish line. The bodies I saw on the ground were those of exhausted, dehydrated runners who had given their best efforts and would soon recover and feel the satisfaction of meeting a challenge. The bodies on the ground this year were different. Many won't recover and feel success. Many will be forever changed by the events of the day and all of us will have changed in some way by knowing it happened.

And to think that in 2004, I complained of the heat.