9:52 a.m. – Ottawa police receive reports of an honour guard shot at National War Memorial near Parliament Hill.

Shortly before 10 a.m. – Journalists are among the first to report the sound of gunshots in a Parliament building.

CTV’s Katie Simpson reports a soldier being shot at the War Memorial outside. The soldier is later identified as Nathan Frank Cirillo of Hamilton, Ont.

Members of Parliament tweet that they’re being told to lock themselves in offices. MP Gerry Byrne tweets that RCMP entered the area with “guns drawn” and “machine guns deployed.”

10:12 a.m. – In addition to shots outside, MP Michelle Rempel tweets about shots fired in the Parliament Buildings, near where the Conservative caucus is meeting.

10:18 a.m –Tony Clement reports more than 30 shots fired as MPs flee Parliament for safety.

10:20 a.m. – Prime Minister Stephen Harper’s director of communications says the prime minister is safe and has left the area.

10:21 a.m. – MP Bob Zimmer tweets that a “lone gunman” is deceased. The suspect is later identified as Michael Zehaf-Bibeau, a Canadian citizen born in 1982.

10:25 a.m. – RCMP tweets first statement urging public to avoid Parliament Hill "due to ongoing police incident.”

10:49 a.m. – CTV Ottawa Morning Live tweets that the Rideau Centre shopping mall has been evacuated.

10:53 a.m. -- RCMP advise the public to stay avoid downtown Ottawa.

11 a.m. -- Twitter users report shots being fired at Chateau Laurier, a hotel not far from the Parliament Buildings. Reports were unconfirmed.

11:06 a.m. – University of Ottawa goes into lockdown with message sent to students: “LOCKDOWN in effect. Stop all activities. If possible, close and lock the door, and turn off lights. Silence cell phones. Keep away from doors and windows. If it is safe to do so, close blinds. Take cover and remain quiet until authorities instruct otherwise.”

11:13 a.m. – Police with guns drawn outside the Chateau Laurier. The building is locked down.

11:13 a.m. – Parliamentary security sends out an advisory:

“ALL BUILDINGS are currently in lockdown. Follow the instructions from Security Services.

THIS MEANS stay in your office, with the doors locked and away from the windows. If your door does not lock, find a way to barricade the door, if possible. Do not open a door under any circumstances.”

11:25 a.m. – Ottawa Police confirm two separate incidents: one near the National War Memorial and one on Parliament Hill

11:35 a.m. – Sources confirm that the shooter on Parliament Hill is dead.

11:48 a.m. – CTV Ottawa Morning Live reports the US Embassy is locked down

12:11 p.m. – NORAD releases a statement: "NORAD taking appropriate and prudent steps to ensure adequate posture to respond quickly to any incidents involving aviation in Canada."

1:20 p.m. – Sources confirm Cirillo, the soldier shot at the National War Memorial, has died.

1:30 p.m. – The NHL postpones a hockey game between the Toronto Maple Leafs and the Ottawa Senators. The puck was due to drop in Ottawa at 7 p.m., but will be played at a yet-to-be-determined date later in the season.

1:44 p.m. – The lockdown at the Rideau Centre shopping mall is lifted. Despite earlier reports of a shooting in the area, only incidents on Parliament Hill and at the National War Monument are confirmed by police.

2:10 p.m. – Ottawa Police and RCMP hold a press conference, officially confirming the deaths of both Cirillo and Zehaf-Bibeau inside Parliament Hill. Police could not say if other suspects are on the loose. Authorities also ask people to report anything suspicious and to avoid the downtown core.

2:30 p.m. – Harper speaks with U.S. President Barack Obama by phone. A statement says Obama called “to express the American people’s solidarity with Canada” in the wake of attacks on Canadians Forces in Quebec and Ottawa. “President Obama condemned these outrageous attacks, and reaffirmed the close friendship and alliance between our people.”

2:35 p.m. – FBI confirms they are assisting authorities in Ottawa.

3:45 p.m. – Lockdown lifted at the University of Ottawa, though classes and exams remain cancelled. The school says activities will resume tomorrow “unless otherwise advised.”

5:10 p.m. – A “safety perimeter” reduced in size, Ottawa police announce. Residents inside the perimeter asked to stay indoors until further notice.

7:10 p.m. – Security officials reinstate a lockdown for some offices around Parliament Hill as Prime Minister Stephen Harper prepares to address the nation.

8:08 p.m. -- In a televised address to the nation, Prime Minister Stephen Harper says two “despicable attacks” on Canadian soldiers this week will not weaken the country’s resolve to fight terrorism at home and abroad.