A calm, quiet evening in Toronto gave birth to an anxious late night mob when, seemingly out of nowhere, fireworks started going off along the waterfront.

Really loud ones. Lots of them. For about 10 minutes straight.

There’s a full on fireworks show going on outside my bedroom window right now. I have no idea why, but it’s awesome.pic.twitter.com/SDVQPok13H

— Lauren O'Neil (@laurenonizzle)June 27, 2018

Bright, choreographed bursts of light exploded across the sky near Ontario Place shortly after 10 p.m. on Tuesday.

Twitter, in turn, exploded with worried and ticked off comments.

Hi@gordperks: was there notice given about fireworks at 10 pm (apparently from@OntarioPlace)? Was heard north and in east end as well as Parkdale. Was alarming, especially with sirens now going off :(

— Badass LadyShark (@ladysharkchomps)June 27, 2018

While set off in the city's west end, the fireworks could be seen from east of the Don Valley.

We just watched that from across the Don Valley. North tower of the Eaton Centre is almost directly between here and Ontario Place, and we were able to see the fireworks beyond it.

— total goat rodeo (@auditorydamage)June 27, 2018

The sound travelled an even greater distance. People on Twitter reported hearing booms from as far away as简和邓达斯,Old Mill and Bloor, and evenYonge and Eglinton.

What’s with the cannon fire in Toronto tonight? We can hear and feel the boom out in Etobicoke.# fireworkson a Tuesday night? Alarmingly loud!

— cb (@MyTwitFace123)June 27, 2018

The noise was so intense in nearby residential neighbourhoods like Parkdale and Liberty Village that car alarms were set off all over the place. This proved incredibly annoying for those with early mornings on Wednesday.

Whatevs the fuck that was in#parkdalewith the bullshit excessive ordinance disposal aka fireworks was unwanted and terrible. Fuck you

— Willy Bouchard (@KidVenis0n)June 27, 2018

The display was beautiful, sure...

Over Ontario Place. View from Parkdalepic.twitter.com/JMjwKckZTm

— Kat Taggart (@kattaggart)June 27, 2018

But the sounds were disconcerting — especially for those who couldn't see the actual fireworks.

Gun violence istop of mind right nowin many communities as shootings spike across the city. Four people were killed by guns last weekend alone in Toronto.

Not sure if i’m hearing fireworks or FUCKING LONG RANGE ARTILLERY!! So much for relaxing. Cheers Toronto.. real nice

— Jason Lamplough (@Jasesum)June 27, 2018

There's also the fact that fireworks sound a lot like cannons.

Loud, unexplained bangs are justifiably scary in a climate such as this.

#Torontosad when fireworks prompt us to think the US did something Stupid. Again.

— Boomer (@TorontoT)June 27, 2018

Making matters worse was that nobody, not even the police, had been properly warned about the fireworks show ahead of time.

"Sound of gunshots: Close Ave/ King St.. several shots reported,"reported Toronto Police Operationson Twitter around 10:20 p.m. "Unconfirmed. Unit in the area advises it's possibly fireworks. They are checking the area."

Update: unit has confirmed, Fireworks....no gunshots.#GO1165232^adc

— Toronto Police OPS (@TPSOperations)June 27, 2018

As it turns out, the display was put on by the organizers ofROTARYFESTat the Canadian National Exhibition Centre.

"Ah ha. Rotarians,"commented Shawn Micallef. "How will the Shriners top this?!"

How, indeed?