Rear Window Defogger problems of the 2004 Chevrolet Suburban

Our family was not home, the car has been parked in the driveway as normal. My neighbors were in the yard and suddenly heard what sounded like an explosion. They looked over and the rear window had shattered and blew the gate open. It also melted the plastic that holds the glass. It seems as if possibly the rear defroster may have been faulty although the vehicle has not been moved in 3 days. Glad someone was not standing behind it. It blew glass about 10 ft. Waiting on ins to call back.