9:03 a.m.: A second plane United Airlines Flight 175, also a Boeing 767 flying from Boston to Los Angeles, crashes into the south tower and explodes. Both towers have huge holes ripped in them and are burning.

9:40 a.m.: For the first time in American history, the Federal Aviation Administration shuts down air traffic across the United States.

9:43 a.m.: American Airlines Flight 77, a Boeing 757 flying from Washington, D.C. to Los Angeles, crashes into the Pentagon, headquarters of the American Dept. of Defense.

9:45 a.m.: The White House is evacuated. Within the hour, all federal office buildings in Washington are evacuated.

10:05 a.m.: The south tower of the World Trade Center collapses, producing a massive cloud of debris.

10:10 a.m.: One side of the five-sided Pentagon collapses. A fourth hijacked airliner, United Airlines Flight 93, a Boeing 757 flying from Newark, N.J. to San Francisco crashes near Pittsburgh.

10:24 a.m.: All transatlantic flights to the United States are redirected to Canada.

10:28 a.m.: The north tower crumbles from the top down, sending debris and smoke down through the streets of south Manhattan.

11:02 a.m.: New York Mayor Rudy Guiliani orders an evacuation of Manhattan Island south of Canal Street.

12:15 p.m.: The American immigration service says the borders with Canada and Mexico are at the highest state of alert.

1:04 p.m.: President Bush speaks from an air force base in Louisiana. "Make no mistake, the United States will hunt down and punish those responsible for these cowardly acts."

1:44 p.m.: Two aircraft carriers and several destroyers are ordered to position along the east coast to provide radar and refueling support for an upgraded air defence.

2:30 p.m.: The FAA says there will be no commercial air traffic until noon Eastern time at the earliest.

5:20 p.m.: Building 7 of the World Trade Center complex, a 47-storey tower, collapses after being damaged by the destruction of the twin towers.

6:00 p.m.: Television stations carry images of explosions and fires in Kabul, Afghanistan. U.S. officials will later say the United States is not involved in the incidents.

8:30 p.m.: President Bush addresses Americans on television. "Today, our fellow citizens, our way of life, our very freedom came under attack in a series of deliberate and deadly terrorist acts…Thousands of lives were suddenly ended by evil, despicable acts of terror."

Sept. 14, 2001
Memorial services are held in Washington, D.C., Ottawa, London and elsewhere. STORY

Sept. 20, 2001
President George W. Bush addresses Congress. TRANSCRIPT

Sept. 22, 2001
President Bush lifts economic sanctions against both India and Pakistan. Pakistan, which borders Afghanistan, has recently agreed to share intelligence reports with the U.S. and to let American military planes fly in its airspace.

Oct. 2, 2001
Fear of biological and chemical weapons is sparked when American Media Inc. employee Robert Stevens is hospitalized after inhaling anthrax. He dies three days later. More incidents of anthrax exposure and positive tests for the bacteria are reported by U.S. government employees, the postal service and media organizations. A hospital worker in New York and two postal workers in Washington die. Ottawa announces plans to spend almost $12 million to fight bio-terrorism.

Oct. 7, 2001
U.S. and British forces launch the first wave of air strikes in Afghanistan. President Bush says targets will include training camps and military installations belonging to Afghanistan's Taliban leadership and Osama bin Laden's al-Qaeda organization. Gunfire and explosions are reported in several places, including the capital city of Kabul and the southern community of Kandahar.STORY
The same day, a statement made by Osama bin Laden is broadcast on the Arab television station Al-Jazeera, praising those responsible for the Sept. 11 attacks. The video was apparently made before the air strikes.

Oct. 15, 2001
A new anti-terrorism bill is introduced in the House of Commons. Bill C-36 would give police new powers of arrest, investigation and surveillance, including allowing suspected terrorists to be detained without charge for up to three days and allowing judges to compel witnesses to give evidence during an investigation. Critics of the bill say it undermines civil rights and warn there are insufficient measures to ensure the powers aren't abused. (The bill becomes law on Dec. 18, 2001.) STORY

Oct. 17, 2001
More than 900 Canadian troops ship out from Halifax headed to the Arabian Sea to join U.S. and British forces. They leave aboard three Canadian vessels, HMCS Charlottetown, HMCS Iroquois and the supply ship Preserver. The mission is called Operation Apollo. Two other Canadian frigates have already left to participate in the U.S.-led effort, and a sixth ship will join later. STORY

Nov. 9, 2001
The Northern Alliance says it has taken the strategic city of Mazar-e-Sharif from the Taliban. Two days later, the Northern Alliance takes the northern city of Taloqan. STORY

Nov. 12, 2001
Reports from Kabul, the capital of Afghanistan, say Taliban forces have deserted the city. STORY

Nov. 15, 2001
Defence Minister Art Eggleton announces that Canada plans to send up to 1,000 soldiers to Afghanistan, providing short-term stabilization to allow for the entry of humanitarian assistance. Troops from CFB Edmonton's Third Battalion, Princess Patricia's Canadian Light Infantry, are put on 48-hour notice. STORY

Nov. 22, 2001
A bill aimed at enhancing public safety regarding biological and chemical weapons is introduced in Parliament. Bill C-42 is read for the second time on Dec. 3 but remains to be made into law. STORY

Dec. 7, 2001
The city of Kandahar is taken from the Taliban. STORY

Dec. 13, 2001
The U.S. government releases a videotape, translated into English, of Osama bin Laden talking about the Sept. 11 attacks with several other men. According to the translation, bin Laden says the number of casualties was "calculated in advance." STORY