The accident occurred when the tailgate opened without warning or any buttons being pushed while towing a boat trailer. The tailgate become bound between the truck and trailer. The tailgate was damaged and limited my ability to turn the truck. My truck is normally parked in a garage and doesnât sit in the weather. This truck is my 3rd vehicle so it doesnât really get driven unless it is pulling a trailer, I tow with it all the time but very rarely use the bed or tailgate. Monday June 16 â Drove from Gallatin, Tn â Eddyville, Ky â Paducah, Ky the weather was constantly heavy rain and wind. Tuesday June 17 â Drove from Paducah, Ky to Defeated, TN more of the same bad storm. There were 3 of us and no one opened the tailgate, we hooked up to my boat and drove less than a quarter mile to the boat ramp, when we arrived, the tailgate had opened and the stairs on the boat had impacted the small part of the tailgate during a right turn. Prior to leaving the driveway and after hooking up the boat I had to back up slightly and remove pressure to remove the chock block from the boat trailer tires. (I would have noticed that the tailgate was open) this happened with no warning, put me and my passengers at risk and did over $1000 dollars in property damage. I was expecting GM to replace the parts that were faulty and the small part of the tailgate that was damaged. I returned twice to Larry Stovesand GMC and had them access the switch. They have refused to supply