The recent failure of the Antares rocket shortly after launch was an awful thing to watch. Thankfully nobody was injured, but seeing the loss of the rocket itself and the Cygnus spacecraft carrying supplies and science experiments to the International Space Station was alone very upsetting. A lot of time and hard work of many scientists go in to every launch.
Though the cause of this irregular launch is currently being investigated, National Geographic's Brad Scriber described the explosion and the task of the Range Safety Officers whose job it is to monitor rockets during launch and terminate the flight by remote detonation before they pose serious threats to nearby populated areas.
Why NASA blew up a rocket just after launch. By Brad Scriber.