Side/rear Glass problems of the 2008 Ford Taurus

The weather was cold. . . Well below zero (about 10-15 degrees f below zero). The car had been sitting outdoors. The defroster was running to keep the vehicle windshield clear. About 10 minutes into the ride, the windshield spontaneously cracked all the way across from driver's to passenger's side, a distance of over 4 feet. There was no nick or stone chip in the windshield prior to the crack. It did not put glass inside the vehicle compartment, but could potentially have impaired vision enough to cause an accident.