Defroster/defogger/hvac System Rear Window problems of the 2015 Ford F-150

While driving on the freeway with defroster on in rainy weather conditions, the rear window spontaneously shattered and made a very loud popping sound as though it exploded. There was no impact that caused the spontaneous shattering. Three children under the age of 9 were seated in the back in car seats / booster seats. The windows behind them broke. They were in danger of the entire window falling through until we could safely exit the freeway and pull over. Upon parking, the window fell through and tiny pieces glass fell into the the truck bed and onto the back seats. No one was injured, though the children in the back were distressed by the incident. The entire back window was completely shattered and the edges of the window were cracked in a jagged pattern. And insurance claim was filed. No police report or other inspections have been completed by insurance or the dealer. There was no warning signal that we in danger of the window spontaneously shattering. The vehicle is available for inspection upon request.