It's hard to believe, but this week marks the 20th anniversary of the Space Shuttle Challenger disaster, a disaster many of us watched unfold live on television.
It's one of those moments in American history that punches you in the gut and momentarily takes your breath away, and people of all walks of life remember it vividly still.
"Four, three, two, one, liftoff. Liftoff of the 25th space shuttle mission, and it has cleared the tower."
January 28, 1986. 11:39 a.m.:
"Engine throttling up at 104 percent."
"Challenger, go with throttle up."
"Roger. Going with throttle up."
The Space Shuttle Challenger exploded 73 seconds after takeoff, killing all seven astronauts on board.
David Hechler says, "I just remember things falling from the sky. I turned on the television and there it was."
Goldie Hechler says, "The explosion, pieces going all over the sky, falling, and not realizing immediately what happened."
Miguel Monroy says, "I was in Mexico actually, and over there it was big news too."
Gene Sutton says, "They stopped classes to actually show what happened, and then we were devastated."
Barbara Stansell adds, "You just feel like you can't possibly be looking at something true, but it was, and it was very sad."
And because school teacher Christa McAuliffe was on board that day, an unprecedented number of school children across the country were watching.
Kathy Safford-Osborne was teaching in Orlando then and had taken her sixth graders outside to watch.
Kathy Safford-Osborne says, "It was especially difficult for me because I had actually had an application for the Teacher in Space Program, but never actually sent it in because at that time I had three small children."
NASA would later blame the Challenger disaster on an O-ring failure in the right solid rocket booster. It was a failure that claimed the lives of Dick Scobee, Michael Smith, Judy Resnick, El Onizuka, Ronald McNair, Gregory Jarvis and Christa McAuliffe.
Dr. Norm Thagard, an astronaut, says, "None of us expect to die. We didn't get into this program to die, but we understand full well that it's a dangerous business."
Astronaut Norm Thagard has flown five shuttle missions including two on the Challenger before its demise. He was training at Kennedy Space Center that day.
Norm Thagard says, "If you sit on a rocket and feel the noise and feel the vibration and then you lift off, your thought is it doesn't take much to go wrong and it's all over, but you always have that childlike faith that it's going to be alright."
Ronald Reagan said, "I know it's hard to understand, but sometimes painful things like this happen. It's a all part of the process of exploration and discovery, the chance of expanding man's horizons. The future doesn't belong to the faint of heart, but to the brave."
Tallahassee's Challenger Center is planning a memorial service on Saturday to remember this 20th anniversary.