Memorials for a slain Hamilton, Ont. soldier continue to grow outside of a local armoury and his family home.

Cpl. Nathan Cirillo, 24, was killed Wednesday while serving as an honourary guard at the National War Memorial in Ottawa.

Cirillo was part of The Argyll and Sutherland Highlanders, an infantry reserve unit based near Hamilton.

Upon learning of the young soldier's death, mourners gathered outside the Hamilton armoury where Cirillo trained, laying flowers and cards outside the gate in his memory.

"He always had a smile on his face, he would always make you smile," Cirillo's friend Peter DiBussolo told CTV News Channel on Thursday.

DiBussolo, who broke the news of the death to Cirillo's cousin, said the soldier was outgoing and loved to laugh.

The young soldier is being mourned by family members and friends, but dozens of people who didn't know Cirillo were also seen leaving bouquets and lighting candles with tear-streaked faces. Some parents told CTV Toronto they brought their children to the memorial, trying to help them understand the significance of the events in Ottawa.

A member of the Hamilton Paramedic Service left a hat bearing the EMS logo. A pair of Hamilton police officers stopped by the armoury with flowers, offering formal salutes to the soldier.

Others wrote condolences on a Canadian flag hung on the brick wall around the armoury.

"God bless our hero," one message read, while others simply stated "Thanks."

"He was a soldier. He fought for Canada. He was one of Canada's own and should be remembered as that," one woman said.

Among the visitors was U.S. Ambassador to Canada Bruce Heyman, who left flowers for the soldier.

"I'm just so hurt for the community and for Canada, and I'm so proud for those that came to the corporal's side at his time, and so proud of those who reacted in the community," Heyman told media.

Ontario NDP leader Andrea Horwath stopped to pay her respects at the armoury vigil, telling reporters she felt sad and worried about the attack, but also respectful of those who train at the armoury as Cirillo did.

A similar vigil is forming at Cirillo's childhood home. Balloons, flowers and cards lined the fence around the red brick house, thanking the soldier for his service.

One neighbour lined the soldier's street with Canadian flags, calling it a small token of thanks.

"He's defending our country, our freedom," neighbour Vic Colville told CTV Toronto's Colin D'Mello after placing the flags along the street. A police guard sat outside the Cirillo home through the night.

"Our thoughts and prayers are with his family," Lt-Col. Lawrence Hatfield said of the soldier who was the father of a 5-year-old boy.

Hamilton Mayor Bob Bratina said that the city won't forget Cirillo's service.

"Hamiltonians will have a much greater respect and understanding for people who put on the military uniform, because sadly it seems in the events of the last couple days, that uniform is a target."

Flags across the city have been lowered in honour of Cirillo, and Hamilton will host a memorial service in the days to come.

Residents of Hamilton can sign a book of condolences sitting at City Hall, and there will be a prayer and wreath ceremony held by the Muslim Council of Greater Hamilton at the armoury at 2:30 p.m.

A community memorial Facebook page in Cirillo's name was established late Wednesday afternoon. By Thursday afternoon, the page had more than 133,000 "likes."

With reports from CTV Toronto's Colin D'Mello and Austin Delaney