While driving and mid-turn, 2 alerts were announced (park assist not available; steer assist reduced) and I immediately lost the ability to turn the steering wheel (it was 100% stiff) mid turn and was almost t-boned by a vehicle in on-coming traffic. I was able to make the turn widely and pull car to the side while blocking the only lane of traffic. I had ZERO warning and ZERO ability to turn the wheel even into a simple driveway. There was a parking lot near and I couldn’t turn the wheel just to turn into it. This almost caused a huge accident which I could have been killed in. Luckily my children were not in the car. If the car can just stop working with no warning, it is not safe to drive in my opinion.