I must have pressed the trunk button while I changed the battery in my fob. It never happened before perhaps because I was beyond the transmitter range but yesterday I was closer to the vehicle. Thank God my good neighbor texted me as my trunk was opened for about 2 hours and it started to snow...The way I park and the way the house is built, I couldn't see through the windows or front door. Lesson learned, next time I change the fob battery I'll make sure the trunk is closed!