Avid concertgoer Mark Churaman can't shake the disturbing images of the suicide bombing that tore through the Manchester Arena on Monday night.
He was at the venue himself a few years ago and remembers filing out of the same rows of seats where hundreds of unsuspecting teenagers ran for their lives.
And he's stood inside the vast foyer where many of the 22 victims died when an explosive ripped through the space.
``It made my stomach roll,'' the 32-year-old Toronto resident said of hearing the details about the terrorist attack at the Ariana Grande concert.
``I can only imagine the chaos and madness that must've occurred there.''
Churaman, who estimates he's attended more than 300 concerts since he was a teenager and sees roughly 30 shows every year, said he was also shaken by the November 2015 terrorist attack at the Bataclan in Paris that left 89 people dead.
``Any time I go to a show now the thought does cross my mind, what if something happens,'' he says.
``Concerts are supposed to be an escape from the darkness and the negativity of the world.
``But I do try to not let that affect the moment.''
Some venues are taking extra steps to ensure concertgoers feel safer in the coming weeks, even if there isn't any sign of imminent danger.
Heightened security is planned for Toronto's Air Canada Centre where Canadian superstar the Weeknd is scheduled to play back-to-back shows this weekend. Other international stars like the Chainsmokers and Neil Diamond are slated for the coming weeks.
Dave Haggith, a spokesman for the ACC's owner Maple Leaf Sports & Entertainment, said more security staff will be on the grounds for these events.
While he declined to offer details on whether other security measures would also be taken, he acknowledged that more was being done.
``You're always looking for best practices and communications so you're ahead of the game as best you can be,'' he said.
Haggith said the ACC regularly works with local and national law enforcement to monitor any perceived threats. Toronto police said they have no reason to believe there's an increased threat level in the city.
In recent years, the venue began ramping up security with walk-through metal detectors and bomb-sniffing dogs.
``You're going to find every venue is at a heightened awareness,'' Haggith said.
``Something like the incident that happened yesterday brings a much more public focus to it.''
Churaman said he's not changing any of his concert plans despite his lingering apprehension. He's already bought tickets to see the Weeknd's show on Friday.
``I'm very excited about it, but I know myself and I know I'll be thinking about what happened ... in Manchester,'' he said.
``This is going to be something that's going to be heavy in a lot of people's hearts over the next little while.''