The headlines and bloodied images that are being used to tell the horror story of Boston are a grim reminder to us all; a reminder that we never know what's on life's next page.
We know what Monday was meant to be about; one of sport's great challenges and races in one of the world's great cities.
Yet the news and pictures would fit more comfortably with a description of a battle scene.
And in the smoke, the panic, the rush to help, the screaming, the noises and the shock, many here will be reminded of our own bloody days.
That scene in Boston that we watched through hours of continuous news coverage could so easily stretch across onto the Shankill Road, into Enniskillen, or Omagh, McGurk's Bar and countless other places identified with conflict.
It is an all-too-familiar image, not confined to any one corner of the world, but something that can be painted across an international canvas.
And in these scenes, no matter where they are, there are the stories of bleeding and broken people, the dead and the injured, but also the lucky ones.
Into this category, we fit those who were nearby, yet just far enough away to be safe.
And, coming up to half-past-one yesterday morning, I heard from one such person; an old running friend, Mike Roberts.
By chance, I had coffee with him last Friday, when we bumped into each other in our home town of Holywood.
And, as we chatted, he told me he was leaving the next morning to compete in the Boston Marathon, that classic distance of 26 miles 385 yards that he was hoping to cover in three hours 40 minutes.
So, on Monday I was thinking about Mike Roberts as I looked at the finish line clock on the television news reports from Boston, the clock that showed the first explosion at around four hours and 10 minutes into the race.
And I thought that, if he had achieved his target, he would have been through that finish line about 30 minutes earlier.
But his run took longer than expected, something he described to me in a number of text messages, the first of which arrived at 1.27am yesterday.
"Brian, I had a tough race 3.51 [three hours 51 minutes] and was in the medical tent at the finish when the bomb went off," he wrote.
"Sadly, I recognised the sound. The casualties were wheeled in past me.
"I was fortunate. Boston shut down. So like old Belfast."
A few minutes later, when I got him on the phone, his first words were: "I'm safe."
Then he described to me being "shell-shocked" at the end of the marathon distance, feeling a little bit "wobbly" and being taken into the medical tent.
Roberts is now 61. I first met him in the 1970s, when he was a Northern Ireland sprinter who specialised at 400 metres; close to the bolt-on closing distance at the end of the marathon's 26 miles.
From experience, I know how that race journey can hurt every bone in the body, can leave you feeling shell-shocked and wobbly and in need of some attention.
But, in Boston on Monday, Mike Roberts was alert enough – sharp enough after that stamina-sapping run – to know what was happening when he heard the first bang and then the next.
To those beside him, he said: "I'm from Belfast. I recognise that sound." He later told me it reminded him of 1972 and the bomb blitz that came to be known as Bloody Friday.
And, yesterday, on radio in Belfast, he told his story from Boston; how he was fortunate on a day when people died and others were injured and on a day when another bloody image was painted into the memories of so many.
For those in Boston, it will be a scene that won't easily be deleted. And Mike Roberts's story of being close by, yet just far enough away to be safe, can also read into what happened here over the decades of conflict.
There were many such lucky escapes; stories of people who changed their minds and plans at the last minute and in so doing didn't walk into the many bombs.
And stories of people who passed minutes before an explosion, or who arrived at a scene, a street, or a road, just minutes after a blast.
That finishing stretch in the Boston Marathon, those pictures of smoke and dust and panic and fear, those noises, including the screams and the words of shock, will bring many scenes back into our thoughts and thinking. On Friday, when he left me and I shook his hand and wished him luck, I expected that my next conversation with Mike Roberts would be about his run, his time, his experience in Boston.
But we have something very different to talk about, the story that came in a page-turn that none of us expected.
It's not a story of the physical hurts that come with stepping out and running out over that marathon distance.
Rather it is a story of bombs and of broken and bleeding people; something that happened far away, but close enough to trigger memories of things that happened here – yet another bloody reminder.