Hero of Canada's Parliament Shooting Greeted With Standing Ovation

— -- The hero sergeant-at-arms who killed the alleged shooter in Wednesday's attack on the Canadian Parliament was welcomed back into the building this morning with a prolonged standing ovation.

Kevin Vickers, 58, nodded to acknowledge the spontaneous applause that washed over him by the officials in the chamber, which included Prime Minister Stephen Harper.

Vickers, a retired Royal Canadian Mountie, holds the ceremonial post of sergeant-at-arms but he confronted and killed gunman Michael Zehaf-Bibeau, the suspect in the shooting death of a soldier at the National War Memorial before invading the main Parliament building.

Parliament was back to work this morning, and the crowd ushered Vickers into the room with applause which went on for several minutes. At one point, a few tears appeared to roll down his cheek. The Members of Parliament then sang the national anthem, and held a moment of silence for the slain soldier, Corporal Nathan Cirillo.

Harper honored Vicker's "great work"and strode the length of the hall to shake Vickers' hand. The prime minister was the first of several Parliamentarians to praise him and conclude by walking to his desk to shake his hand.

The prime minister noted that he received calls from world leaders including President Obama and seemed particularly touched by the gesture of American hockey fans who sang "O Canada" at a Pittsburgh Penguins game Wednesday night.

"So thank you to our friends in the U.S. and around the world," Harper said.

Vickers later issued a statement saying, "I am very touched by the attention directed at me following yesterday’s events."

Authorities in Canada are trying to understand what motivated a gunman to kill the soldier with Harper calling the shooting the country’s second “terrorist” attack this week. During his remarks this morning, Harper continued to connect the two attacks, saying that they were perpetrated by "young men born and raised in this peaceful country" who turned their backs on the values that they were taught.

Harper said the intent of the attack "was to instill fear and panic in our country and to interrupt the business of government."

"Canadians will not be intimidated... We will be vigilant but we will not run scared," Harper said.

The details about the attack are still being investigated, but a masked gunman killed Cirillo, 24, while he was standing guard at Ottawa's war memorial

Following the 9:52 a.m. shooting, the suspect stormed Parliament but was shot to death by Vickers, authorities said.

The gunman, Zehaf-Bibeau, was a 32-year-old Canadian who had recently converted to Islam, ABC News has learned.

Canada had already raised its national terrorism alert level following an incident Monday in which a Canadian soldier was killed in a hit-and-run by a man suspected to have been a radicalized jihadist.

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