On January 1st driving east bound on road 520 in central florida. I was driving around 65mph when the vehicle suddenly shut off. The displayed showed a warning saying that something of the sort that I needed to press the brake to start the engine even though I was driving normally. I had to coast to the side of the road and I pressed the brake. once the brake was engaged the vehicle immediately went to park and will not start. I press the ingition button and the screen would go blank and no sound or warnings were displayed. I had to call the police to provide a safety as the vehicle was in a very dangerous area and all my family was on the vehicle. the police laid down flares and I contacted a tow truck using onstar. Onstar was unable to communicate with the vehicle to diagnosed the issue and no warnings or errors were displaying. The vehicle was towed to Carl Black Chevrolet of Orlando Florida. The dealer stated that the engine is locked (L87) and was not able to turn, therefore the vehicle ds not start. The dealership technicians have informed that the vehicle needs a new engine and GM needs to approved, the vehicle is still under warranty and I’ve contact GM and until today, 17 days later, GM has not responded or allowed the dealership to fix my vehicle.