Apparently a glitch caused the entire San Diego fireworks show to go up in less than 20 seconds...
http://latimesblogs.latimes.com/lanow/2012/07/entire-san-diego-fireworks-show-exploded-in-15-seconds-ruining-show.html
http://latimesblogs.latimes.com/lanow/2012/07/entire-san-diego-fireworks-show-exploded-in-15-seconds-ruining-show.html