In December 2009 while training a new pump operator,and going through different procedures, they decided to spray a little water out the deck gun. Be aware this is a 2002 pumper in excellent shape and well maintained. As the pressure got up around 180 lbs the deck gun nozzle suddenly shot off and took the telepole scene light with it.If anyone had been standing near the truck they could have easily hurt or killed. Seems the set screw that holds the nozzle where it rotates on a ball bearing got loose and the end shot off.
Truck maintence needs to look at everything and you should prepare for the unusual.