Just a few weeks ago, in fact, you could have bumped into the Danish royal couple, and vied for a handshake with no more than ten other people.
Maybe it's because Ottawa is usually so serene, so tidy, so predictable, that the gravity and the danger of what unfolded Wednesday morning seemed to take a long time to sink in.
Tourists with suitcases, students, bureaucrats in their suits, even a woman with a stroller milled casually around a makeshift police perimeter just two blocks from the spot where a Canadian soldier had been gunned down in cold blood — aware of what was happening, but not quite believing it.
"Get out of here! Run!" a police officer barked at office workers just a five-minute walk from the National War Memorial, waving them frantically into a nearby building. Once inside the building, security personnel kept people away from the windows.
The same scene played out in the streets around Parliament Hill and beyond. People who happened to be standing outside the Rideau Shopping Centre, a busy mall two blocks from the Hill, were suddenly told by officers to hit the ground and take cover as police vehicles sped past.
For hours, confusion reigned. Nobody quite knew where they should go.
"You're not safe here," an officer told reporters outside the National Arts Centre, south of the War Memorial.
"If you can see Parliament Hill, you're in danger!" an officer yelled in Major's Hill Park, across the Rideau Canal from the Hill.
Even witnesses to the brutal murder of honour guard Sgt. Nathan Cirillo, who was shot twice at point-blank range, appeared stunned into disbelief and frozen in the moments afterwards, said witness Tony Zobl, who watched the scene unfold from a fourth-floor office window.
"I don't know whether they thought it was some kind of spoof coming up to Halloween," he said of the frozen bystanders.
Soon the core of the city, usually clogged with city buses and pedestrians, was emptied of everyone but swarms of police, some clad in black and toting assault rifles. Helicopters throbbed overhead. People who happened to be outside were locked out, and those inside were locked in.
"I think it's scary because this stuff just doesn't happen in Ottawa," said downtown worker Kayla Rain. "It's quiet, it's weird."
Several people gathered around hastily erected barricades with cellphones and tablet devices taking pictures and videos. A couple took a selfie of themselves with the surreal scene around Parliament Hill in the background.
Gord Cowan from Medicine Hat, Alta., sat with his suitcase watching the police movements. He had been locked out of a meeting of the Insurance Brokers Association of Ontario at the Chateau Laurier hotel, which sits cheek-by-jowl with the War Memorial and Parliament Hill.
"All of a sudden there was an enormous police presence and officers running around with guns drawn. It's something you just don't see in Canada," said Cowan.
"It's amazing.... you've got downtown Ottawa, you've got police with automatic weapons drawn running through a crowd of people — it's just bizarre."
Isabelle Parent-Carson found herself locked inside the Ottawa Convention Centre for hours.
"It was stressful because we didn't quite know what was happening," said Parent-Carson.
"We knew that someone had been shot at, but we didn't know whether there was one shooter, two shooters. It's a bit of a shock because we don't see that type of thing here."
While MPs were talking of a new reality in the capital and a loss of innocence, Parent-Carson was more sanguine.
"It doesn't change my impression that we're safe here in Ottawa," she said. "We're not going to take things out of proportion."
— With files from Steve Rennie and James McCarten
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