This month marks the 50th anniversary of John F. Kennedy‘s assassination—an event that shook a nation and whose effects are still felt today. The new book, Where Were You? America Remembers the JFK Assassination, a companion to the two-hour NBC documentary event Tom Brokaw Special: Where Were You (Friday, Nov. 22 at 9 p.m. ET), includes essays by politicians, celebrities and media personalities remembering where they were on November 22, 1963.

We’re publishing a series of these reflections in the weeks leading up to Nov. 22. The third, from Secretary of State John Kerry, is below.

The day he died is indelible, obviously, for all of us. I was playing in the Harvard-Yale soccer game, and I heard a ripple. I was playing, and I came out, sat down on the bench, and heard this ripple of conversation and concern and audible gasp go through the audience. The word was: “The president has been shot.” We didn’t know what had happened or anything. I remember just being completely disconnected from the game. It was just a shock. I mean everybody felt like, “What are we doing? We’re playing a soccer game, and the president’s just been shot.”

We played out the game, and we learned before the game had ended that he had died. It was sort of a lost period of time. I can’t tell you to this day who won. I don’t know. I’ve never gone back and found out. It was such a state of shock for everybody that this could happen in America to the president. Notwithstanding that historically we’ve lost too many presidents to assassination. It’s sort of stunning when you go back and look at it.

There was a sense of turning everything upside down, a total sense of the order of things having come apart somehow. I remember being with my roommates; we spent the entire weekend glued to the television. Then of course you watched this next moment of surreality, when Lee Harvey Oswald was killed by Jack Ruby. We were all trying to find some meaning in it. How do you find meaning in something like that? I remember walking around New Haven at two or three o’clock in the morning with a cousin who came down to spend some time with me because he knew I was involved in the politics and involved personally. At that moment I remember saying, “We have to make sense out of this. We, all of us, have to find a way to do something that makes it right.” It was a very strong feeling of a responsibility to lead a life that made a difference somehow.

Regarding possible conspiracies, to this day I have serious doubts that Lee Harvey Oswald acted alone. I certainly have doubts that he was motivated to do that by himself. I’m not sure if anybody else was involved. I don’t go down that road, with respect to the grassy knoll theory and all of that, but I have serious questions about whether they got to the bottom of Lee Harvey Oswald. I think he was inspired somewhere by something, but I can’t pin anything down on that. I’ve never spent a lot of time on it. But I think, after a certain period of time, and that period of time may well have passed, it is totally appropriate for a country like the United States to open up the files on whatever history can be shed light on. I think that is appropriate. It has to be done in the right way, by the right entities or people, but certainly by a valid historian or for some valid analysis; I think that everybody would benefit.

Excerpted with permission from Where Were You? America Remembers the JFK Assassination, compiled and edited by Gus Russo and Harry Moses, foreword by Tom Brokaw, published by Lyons Press © 2013.