The sun is rising on the Rideau River on a Sunday morning as a crew of 18 prepares to blow it up.
For more than a century, Ottawa has been besieged by these non-polemical blasts: Pre-empting the annual thaw, city workers armed with sticks of dynamite set off explosions where the frigid waters tumble over the Rideau Falls and into the Ottawa River.
The process costs the city $460,000 a year, mitigating the risk of water damaging hundreds of nearby buildings. With a mix of delicate prep work, a tractor-boat hybrid called an Amphibex that helps smash and dash the ice - as well as teeming eruptions - the team works to stop blocks from forming a frozen, impenetrable wall at the foot of the electrical dam that towers above the falls.
Dressed in bright orange flotation jackets and hip waders in -11 C weather, the workers are ready for two or three days of steady detonation. With a mechanical saw, they have sliced up the ice into long rectangles that wait to be carried by the current through controlled openings in the dam. With powerful augers, they have drilled hundreds of foot-deep holes, ready to receive their charges.
On the Sussex Bridge above, a pickup truck is the centre of attention - safety is paramount on this day. The driver steps out into the winter wind and opens a locker-like contraption at the back that is specially designed to carry its cargo: hundreds of kilograms of red tubes that look like they fell off the back of Wile E. Coyote's truck. The driver takes out the packs of dynamite and places them in a sled.
Another Ottawa city worker delicately puts a handful of wires and caps into his front pouch, and brings everything down to the water level, less than a minute's walk away.
When a whistle goes off, the whole area goes quiet.
Two packs of explosives are wired-up and sent drifting under the ice in the speedy current. Standing on the dam, a blaster with two decades of experience "gives the juice," and the annual dynamiting of the Rideau River has begun. Chunks of ice and water take flight. Slabs are quickly unleashed and zip down over the falls.
From afar, crowds gather throughout the day to witness the event. For them, the blasts are a more precise indicator of the nearing end of winter than any prediction divined from a groundhog.
As the first explosion resonates through the city, blaster Peter Redsell announces, "Spring's here."