OUR 2009 GMC YUKON DENALI WAS TOTALED IN A CRASH. THE BATTERY WAS DESTROYED ,CUTTING ALL ELECTRICAL POWER TO THE VEHICLE. THE DOORS,WHICH AUTOMATICALLY LOCK WHEN IN DRIVE, WERE LOCKED, AND IN HER CONFUSION COULD NOT EXIT THE VEHICLE. THE COMMUNICATIONS EQUIPMENT WAS ALSO USELESS. THERE NEEDS TO BE A BACKUP BATTERY IN A LESS VULNERABLE LOCATION. *TR