2009 Hyundai Santa FE steering problems

I was driving my white hyundai santa fe limited, 3.3l, 6cyl SUV home from work at approximately 4:30 pm eastern standard time. I was driving on the expressway at 70 MPH when the engine suddenly shuts down and I lose steering control and brakes, veering onto a narrow shoulder and into a slope that sent my SUV into a swamp ditch, submerging the SUV up past the floorboards.

When slowing down to make a turn the engine shuts off. Power steering and breaks are gone. The car will crank right back off but this us very dangerous. I'm not sure if weather is a factor but when it has happened which gas been multiple times, it has been in the 80's. Mechanics and dealership have not been able to find anything and no codes are recorded.