Eleven years ago, terrorists hijacked four commercial airplanes, deliberately crashing two of the planes into the upper floors of the North and South towers of the World Trade Center complex and a third plane into the Pentagon in Arlington, Va.
The Twin Towers ultimately collapsed because of the damage sustained from the impacts and the resulting fires.
After learning about the other attacks, passengers on the fourth hijacked plane, Flight 93, fought back, and the plane was crashed into an empty field in western Pennsylvania about 20 minutes by air from Washington, D.C.
The attacks killed nearly 3,000 people from 93 nations. In New York, 2,753 people were killed, 184 people were killed at the Pentagon and 40 people were killed on Flight 93, according to 911memorial.org.
Though the attacks happened on the other side of the country, the impact was felt nationwide as people all over the U.S. found themselves somehow linked to it.
That morning on Sept. 11, 2001, San Mateo resident Bert Upson was on the 79th floor of the South Tower for a seminar.
Upson still remembers the wails of sirens, the enormous explosion and the white ash that coated faces on Sept. 11, 2001 in New York City like it was yesterday.
But mostly, he remembers the heart-wrenching rush of the World Trade Center towers crumbling.
"Oh God. It’s like nothing else you’ve ever heard. It was like Niagara Falls. It never seemed to stop,'' said Upson, a 79-year-old Palm Desert resident who spends his summers in San Mateo.
Click on the attached videos to view Upson tell his story about how he survived the attacks.
Redwood City firefighter Dan Horton also recalled the horror of 9/11. Though he was not actually in New York on the day of the attacks, he was quickly deployed soon after as part of FEMA’s Urban Search and Rescue (USAR) team.
He and other first responders combed through the mountains of rubble, searching for any sign of life.
Once he returned home to the Bay Area, he remembered to stay grateful for each day he had.
“In the blink of an eye, over 2,000 people were killed,” Horton said. “How does that translate into how many parents, children and families were affected? Enjoy your life, enjoy your friends, your family. They can be snatched away in an instant.”