The explosion of the Space Shuttle Challenger in 1986 that killed high school teacher Christa McAuliffe and six other crew members was one of those tragedies where everyone seems to remember where they were when they learned about it.
For Holly Merrow, Kristin Jacques and Tammy Hickey, the memories are particularly vivid because they watched the shuttle launch on live television as students at Concord High School in New Hampshire, where McAuliffe was their social studies teacher.
Watch TODAY All Day! Get the best news, information and inspiration from TODAY, all day long.
They have paid tribute to McAuliffe since that tragic day by becoming teachers themselves. Hickey is now a middle school physical education teacher, Jacques teaches fifth grade and Merrow is a second-grade teacher.
"She made education real," Merrow told Hoda Kotb on TODAY Thursday. "She brought a real event into the classroom, and I really work hard to bring the real world into my classroom for my students."
Thirty-five years ago on Jan. 28, the three high school seniors wore party hats and blew noisemakers as they cheered on McAuliffe. She had been selected out of 11,000 applicants to become the first civilian teacher in space.
Disaster struck only 73 seconds into the flight off Cape Canaveral in Florida.
"We were in the cafeteria, and everybody was cheering, and it was really loud," Hickey said. "When it actually exploded, we thought it was the rocket booster separating, so we were still cheering.
"One of the teachers was in the cafeteria, and he just said, 'Everybody shut up!' It was dead silent after that."
The spacecraft broke apart above the Atlantic Ocean, killing everyone on board. Investigators later determined that a part had malfunctioned due to the unusually cold January weather and caused a failure in one of the rocket boosters at liftoff.
"I looked at a friend sitting next to me, and there's probably 10 or 12 of us in the room, and I said, 'I think that's supposed to happen,'" Merrow said on TODAY about the initial explosion. "I looked at my chemistry teacher that was there, and she was just crying and bawling."
"I think little by little, we processed it," Jacques said. "But there was that glimmer of hope that we wanted (McAuliffe) and the other astronauts to be OK."
The trio felt her loss immediately.
"She didn't get to teach those lessons she really wanted to teach us," Hickey said. "That's hard to swallow now, you know?"
Just hearing the song "Life in a Northern Town" by Dream Academy, which was played at a memorial at the school after her death, can still bring them right back to that time.
"Every time I hear that, I cry," Hickey said.
The women can remember McAuliffe running to the post office after school to mail her application for the NASA Teacher in Space Project that had been created by the Reagan administration. She kept her students informed of her journey every step of the way until being selected for the program.
"She just made us feel throughout the entire time she was gone training that we were part of it with her," Merrow said.
"It just put her in to such greatness in our minds that she was going to do this," Jacques said.
Jacques added that she struggles when teaching her class about space because of lingering bitterness toward NASA but uses McAuliffe's sudden loss as a lesson for her young students.
"You live every day to the fullest," she said. "You be as kind as kind can be and help those around you. Her life was precious, and everybody's life is precious."