ST. PETERSBURG, Fla. — Saturday marks 20 years since the terrorist attacks on Sept. 11, 2001.
On that morning, 19 members of the extremist group, al-Qaeda, hijacked four California-bound commercial airplanes. In a coordinated attack, two of the planes were flown into the Twin Towers of the World Trade Center, a third into the Pentagon, and the fourth crashed into a field in western Pennsylvania.
There were 2,977 people killed that day, marking the single largest loss of life in a foreign attack on American soil.
Most people who were alive during Sept. 11, 2001, remember just where they were when the terrorist attacks unfolded. Although it may have seemed like time stopped on that fateful day, the events took place in just a matter of minutes.
Here’s a timeline of the Sept. 11 attacks, according to the 9/11 Memorial website:
- 7:59 a.m. - American Airlines Flight 11 takes off from Boston's Logan International Airport en route to Los Angeles.
- 8:15 a.m. - United Airlines Flight 175 takes off from Boston, also heading to Los Angeles.
- 8:19 a.m. - Flight 11 crew members alert ground personnel that the plane has been hijacked.
- 8:20 a.m. - American Airlines Flight 77 takes off from Dulles International Airport outside of Washington, D.C., en route to Los Angeles.
- 8:24 a.m. - Hijacker Mohammed Atta accidentally transmits a message from Flight 11 to air traffic control, apparently in an attempt to communicate with passengers in the plane's cabin. A few minutes later, he sends another accidental message to ground control.
- 8:37 a.m. - After hearing the hijacker's transmission, Boston's air traffic control center alerts the U.S. Air Force's Northeast Air Defense Sector. Fighter planes were deployed but were still on the ground when Flight 11 crashed.
- 8:42 a.m. - United Airlines Flight 93 takes off from Newark International Airport en route to San Francisco.
- 8:46 a.m. - Hijackers crash Flight 11 into floors 93-99 of the North Tower of the World Trade Center, killing everyone on board and hundreds inside the building. First responders immediately mobilize and begin evacuating the North Tower.
- 8:50 a.m. - While visiting Booker Elementary School in Sarasota, White House Chief of Staff Andrew Card alerts President George W. Bush that a plane has hit the World Trade Center.
- 8:59 a.m. - The Port Authority orders everyone in the Twin Towers to evacuate, after initially declaring the South Tower secure just minutes earlier.
- 9:03 a.m. - Hijackers crash Flight 175 into floors 77-85 of the South Tower, killing everyone on board and an unknown number of people inside the building. Similar to the North Tower, the crash renders stairwells impassable and traps several in the building.
- 9:05 a.m. - President Bush is notified that a second plane has crashed into the World Trade Center. At 9:30 a.m., he addresses the nation from Sarasota, calling the events an "apparent terrorist attack on our country" before heading to Sarasota Bradenton International Airport to board Air Force One.
- 9:37 a.m. - Hijackers crash Flight 77 into the Pentagon, killing 59 on board and 125 military and civilian personnel on the ground.
- 9:42 a.m. - For the first time in history, the FAA grounds all flights over or bound for the continental United States.
- 9:45 a.m. - The White House and U.S. Capitol building are evacuated, along with other high-profile buildings, landmarks, and public spaces in Washington, D.C.
- 9:59 a.m. - The South Tower of the World Trade Center collapses in seconds.
- 10:03 a.m. - After passengers and crew members aboard Flight 93 contact friends and family and learn about the attacks, they storm the cockpit in an attempt to take back the plane. The plane crashes in a field in western Pennsylvania, killing all 40 passengers and crew on board.
- 10:28 a.m. - The North Tower collapses after burning for 102 minutes.
- 11:02 a.m. - Mayor Rudolph Giuliani calls for the evacuation of Lower Manhattan south of Canal Street.
- Early afternoon- First responders, volunteers, and search and rescue teams continue the search for survivors through the rubble of the World Trade Center, which is now being referred to as "Ground Zero."
- 5:20 p.m. - The 47-story Seven World Trade Center collapses. The building had been evacuated in the morning, so there are no additional casualties. It is the last of the Twin Towers to fall.
- 8:30 p.m. - President Bush addresses the nation from the White House, calling the attacks "evil, despicable acts of terror. He declares that America and its allies will "stand together to win the war against terrorism."
In the days after Sept. 11, 2001, world affairs seemed to momentarily reorder. Our nation's longstanding allies were joined by longtime enemies to mourn with America in that singularly galvanizing instant.
The 9/11 attacks changed the course of American history forever, with their effects still evident in our daily lives 20 years later.
When former President Bush addressed the nation on the evening on Sept. 11, he made reference to the eventual U.S. military response, saying, “We will make no distinction between the terrorists who committed these acts and those who harbor them.”
American-led efforts to oust the Taliban regime in Afghanistan began on Oct. 7. Osama bin Laden, who claimed responsibility for the 9/11 attacks, eluded U.S. forces until May 2, 2011, when they tracked him down and killed him at a hideout in Pakistan.
The Associated Press contributed to this report.