Truck was traveling through Atlanta when engine shut off and was not responsive. Was able to get truck off the interstate (I285 ramp to I75). Truck would not turn over. Pushed the ONstar button, they stated they couldn’t diagnose the truck. They called a wrecker and got truck to a local GMC dealer(Capitol GMC). Truck was approx. 90 mile away from home. Dealer called on Monday 4/21 and stated that the engine was locked up and would need a new engine.