But the first time many people in the UK heard about what happened was on CBBC's Newsround.
Lots of adults have been remembering how they felt at the time and have been e-mailing BBC's On This Day website.
The website features news stories from the past, on particular days.
Dave remembers how he felt: "I remember getting home from school a little late, turning on the TV to see Newsround's coverage of the explosion. I recall how sick I felt."
And Helen said: "Newsround was the first British programme to show this as it happened."
Among the five men and two women astronauts on board was school teacher Christa McAuliffe.
She would have been the first civilian in space.
The cause of the tragedy was traced to a cracked part which led to a fire and then an explosion.