Not too many details as to what went wrong, just that the whole show fired all at once. This happened in Montreal, once, in the very early days of the competition.

http://www.theatlanticwire.com/national/2012/07/san-deigo-accidentally -set-all-its-fireworks-same-time/54194/

oh my god !!!
saying : the show's producer blamed on a computer glitch

More on this here: http://www.nbcsandiego.com/video/#!/on-air/as-seen-on/Garden-State-Own er-Describes-Misfire/161459195

Wow, that must have been quite something - the article stated that the entire 18-minute display was fired in approximately 15 seconds!

Trav.