Today a generation of young girls’ lives changed forever.
In a northern English city on an ordinary Monday night, thousands of young women and girls went to a big-deal concert.
Ariana Grande doesn't pull in a lot of blokes. Her audience is crammed with mother-daughter duos, sisters and girlfriends. Many are just children, putting their first independent foot out into the world. They came, dropped off by mum and dad, to see their favourite Insta-massive pop star. They came to learn how it feels to be out there, to be part of a crowd who know all the songs they know, moving together.
What they found - as they poured, panicked, out onto chaotic streets - was the brutal reality that they are targets too, now.
Those young women and girls will never feel completely safe in a crowd again, and by extension, neither will we. Not for ourselves, and not for our daughters.
Today, the terrorists - and at the time of writing the Manchester explosions are being treated as an 'appalling' act of terror - have fulfilled their KPIs flawlessly. They have terrified.
The barriers we put between ourselves and horror comfort us, whether we care to admit it or not.
We do it because if horror is something that happens to other people in other places, we can go on with our lives: I don't live in a war zone. My home town is not a dangerous place. I don't walk down that street. I don't go to clubs. I wouldn't do that. I wouldn't go there.
But with news of every fresh atrocity, it seems those barriers are becoming beyond blurred - they've been blown away.
Of course, for Australians, today's atrocity is still somewhere else. Manchester is 17,000 kilometres away. But for many of us, it strikes terrifyingly close to home.