Tears flowed freely in downtown Hamilton on Tuesday as Cpl. Nathan Cirillo, who was gunned down while standing guard at the National War Monument in Ottawa, was honoured with a regimental funeral in his hometown.

Cirillo's funeral procession arrived at Christ's Church Cathedral in just before noon as thousands of onlookers stood silently in the streets to pay their respects to the young soldier. Cirillo's mother Kathy sobbed as she was helped to her seat by members of her son's regiment, overcome with grief as his flag-draped casket was carried inside.

Cirillo's young son, Marcus, followed behind his father's casket, wearing the regiment's cap.

Lt.-Col. Lawrence Hatfield, the commanding officer of the Argyll and Sutherland Highlanders, described the funeral procession as the regiment's "most sacred task."

“A soldier has fallen. An Argyll has fallen. And we, the regiment has been given the honour of taking care of the fallen,” Hatfield said.

“He was a brother in arms.”

The church was full of politicians, members of the military and friends and family of the 24-year-old. Outside, thousands of Hamiltonians stood almost motionless and quiet in the streets, watching the procession of an estimated 4,500 military members as well as police and emergency service members as it moved through downtown Hamilton.

'He understood. He knew what he was protecting and what he was preserving.' —Prime Minister Stephen Harper

Not far away at FirstOntario Centre, several hundred attendees filled three sections of the arena as overflow seating to watch the service on large screens. Inside the arena, people sat, stood, recited prayers and followed the service in the same was as if they were inside the cathedral.

During the ceremony, Rev. Canon Robert Fead thanked Cirillo's family for "allowing Canada to share in their grief."

"Now, he is Canada's son," Fead said. “He gave his life at the most sacred and hallowed ground in this country. His bravery, his sacrifice, is not in vain.”

Cirillo's cousin Jenny Holland shared stories about her life with a man she said has become "Canada's hero." She described Cirillo as a young boy, full of boundless energy and excitement. Later in life, he became a "meticulous" man with a passion for military history and the outdoors, she said.

“His contagious smile and endless laughter were some of the reasons he made friends so easily," Holland said. She also spoke about how much Cirillo's son adored him.

"Not only was he his father," she said. "He was his friend."

Harper praises Armed Forces for dedication

Prime Minister Stephen Harper addressed the congregation as well, praising the men and women of the Armed Forces for protecting Canada's ideals — and Cirillo for keeping watch over one of our country's most "sacred spaces."

“For as long as these ideals have been the foundation of our country, it has been our men and women in uniform who have been in the end, their ultimate guardians,” Harper said.

Most people can't truly understand what it means for members of the military to guard the National War Memorial, and the reverence inherent in that site, Harper said.

"But those chosen for that sought-after assignment … they understand," Harper said. “He understood. He knew what he was protecting and what he was preserving."

After the ceremony, NDP Tom Mulcair said it's important that all Canadians come together on a day like this. "It's a day to honour a fallen soldier and we're thinking first and foremost for the members of his family and his friends here in this wonderful community that's showing such love and support for them," Mulcair said.

Liberal Leader Justin Trudeau echoed that sentiment.

"It's incredibly touching to see so many people gathered to support Cpl. Cirillo, his family and his brothers and sisters in arms," Trudeau said. "It's a moment for us to reflect on the values that he stood on guard for when he was slain and remember we need to continue to honour those values and those principles in this extraordinary country."

'Your Argyll family will not forget you'

The entire country, Harper said during the funeral, was both better for Cirillo's life and diminished by his loss. "I know Canadians everywhere join me in praying for his family," he said. The prime minister also had a wish for Cirillo's son. "May his young son, Marcus Daniel Cirillo, find comfort in knowing our entire country looks up to his dad."

Lt.-Col. Hatfield said Cirillo embodied strength and character and was "loyal, tough, loving and true."

"His family knew it, his regiment knew it, and now Canadians know it,” Hatfield said.

“Rest in peace, Cpl. Cirillo. Your Argyll family will not forget you.”

Soon after, the bagpipes played Amazing Grace and Cirillo's casket was solemnly led out of the church, as a second procession moved through the streets. He was buried at a private interment at a nearby cemetery.

Mourners came from far away to pay last respects. Some broke into spontaneous applause and renditions of O Canada as the men and women of the Armed Forces walked by. The procession made its way through the city using a "slow march," a rare and difficult step meant as a sign of respect for a fallen soldier. 

There were police on almost every corner in the downtown core near the church where the service took place, and many people standing on the edge of the procession route were wearing poppies. Just steps away at the James Street Armoury, tributes have continued to pour in since Cirillo was killed last week. A massive Canadian flag was suspended from two fire trucks over the procession route.

Fund to support the families

An online fund has been set up to collect donations for the families of Cirillo and Warrant Officer Patrice Vincent. Organizers say all of the money raised will be distributed evenly between the two families. They hope to raise $750,000.

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With files from Kelly Bennett and Jeff Green