I wrote this week’s column a day early, sent it into my editors and then, free of any important distractions, sat down to work on my thesis on Monday.

But then it happened. I’m sure you all know this by now, but yesterday, several explosions tore through one of the world’s oldest and biggest sports traditions, the Boston Marathon.

When I found out–and I found out late–I had that sick feeling of déjà vu. It felt like July 7, 2005, all over again.

That day, I had just gotten home from the gym and was sitting, having breakfast, when news of explosions on the London Underground first began to spread. At first it seemed like there may have been some sort of terrible accident, but, bit by bit, the horrible truth was pieced together. It was weird, scary. Not because I felt personally threatened–the little village I was in was safely tucked out of harm’s way in the English countryside–but because I know a lot of people who live and work in London and others who head to town on a regular basis.

Events in 2001 were obviously far, far worse, but 9/11 was surreal. It was a scene from a horrific movie, distant and unbelievable. Too big and devastating to even comprehend.

Boston, like London, though, was terrifyingly real, scarily believable. Living, now, in America certainly made events feel closer to home, but also I know Boston. My best friend moved to the United States when I was in middle school, to Concord, Mass. Every year I’d come out to visit, flying in to Boston’s Logan International Airport.

Worse, my cousin was there this year, in the race.

We used to see each other at least once a year, even after her family moved to the United States. But then life got in the way, and I haven’t seen her in over ten years. We’re Facebook friends, of course, so I know she’s taken up running in a pretty serious way, but that’s not the same. I miss hanging out.

Fortunately, though, she was already back in her hotel room when the first two explosions hit. She could see smoke and pandemonium out the window, but she was safe.

Others, of course, were not as lucky. As I write this, three people have been confirmed dead, and more than 100 more are injured. Many others in the race, the city and across the world will be shocked and saddened, too.

Right now, the exact cause is not yet clear, nor is the suspicion that someone could have been behind this, but with two separate explosions near the finish line, it is hard to imagine that this wasn’t a planned attack. Perhaps by the time you read this, the facts will be clearer.

I’ve written about sports in the face of tragedy before, about the hard decision of whether to play on in the face of such events. The next seven days will bring that question sharply into focus.

This Sunday, the London Marathon, an event every bit as big and prestigious as the Boston Marathon, will be held around the streets of the United Kingdom’s capital. It’s an annual festival that sits close to my heart–I’ve made it across the finish line three times, once dressed as a giant cat.

Organizers, now, are suitably concerned. Any large gathering of people in a free society is inherently risky, because freedom is not something that can be policed. It is something that relies on the good-natured sanity of all present. Changes seem inevitable, not just to tighten up security but also to show respect for those who weren’t so lucky yesterday.

But without question, London must go on, as must the 2014 Boston Marathon. The North American race is the world’s oldest marathon and has been held continuously since 1897–not even two World Wars could interrupt it.

Because the best way–the only way–to remember those we have painfully lost and heal these mental scars is not to give in. To give no quarter to those who might seek to destroy our way of life through violence and threats. To celebrate everything that is good about sports and what it means to live in a free and open society. To play on.

The Stanford Daily’s thoughts are with the victims of Monday’s tragedy. Contact Tom Taylor at tom.taylor “at” stanford.edu and follow him on Twitter at @DailyTomTaylor.