Twenty five years ago the Challenger space shuttle broke apart over a minute after its launch, killing all seven on board. It was both a tragedy and profoundly shocking event, the consequences of which are still being felt today.
Seventy three seconds was all it took.
Millions of people around the world watched as coverage of Nasa's space shuttle launch on 28 January 1986 was played out.
But as the commentary fell silent, and the exhaust trail snaked across the sky, it became clear that something had gone horribly wrong with Challenger's mission.
The shuttle rapidly disintegrated, with the loss of all seven crew.
The flight had been delayed for several days due to freezing weather. An investigation concluded that the seal on the rocket booster had failed because of faulty design unable to cope with the cold weather and other factors.
It was the first time the US had lost astronauts in flight, and it was a profound loss for the country.