2014 Jeep Grand Cherokee brakes problems

The driver pulled the automobile into a driveway on a downhill slope. The driver shut the vehicle off using the push button start/stop. The driver returned to the vehicle 10 minutes later, with a passenger in the front seat. The driver started the vehicle (foot on brake as required) using push button start/stop. The driver engaged the transmission into reverse using the shifting lever (with foot still on brake as is required by the brake transmission shift interlock (btsi) system).

On 12/23/2020 at 6:00am I was driving on long point road when the vehicle completely shutdown - all electrical, engine, lights, breaks, etc. I was driving at approx. 30MPH heading towards a round-about when everything shutdown. The loss of power resulted in not being able to slow down. Luckily there weren't any cars in the round-about when I entered. However, it was a rather tight round-about and was not able to make the turn and I went over the curb and drove straight through the middle of the round-about..