The axle broke while I was driving. I was on CA HWY 101 NB, it was a day after the rain so I was careful not to speed. As I was heading towards a decline the car made a loud pop sound that came from the rear left side. I looked back because my initial thought was the tire popped but as I looked at my rear view mirror the car veered rapidly to the left headed straight to the median. Safety at risk: I tried to break but it seemed like the breaks were not responding well. I turned the wheel to not hit the median and the car turned completely, facing traffic and sliding to the right side of the freeway where it stopped on its side. The car was checked and we have a letter from Toyota saying the part broke due to speeds over 80 mph. But I was not driving over 80, and and axle is probably not supposed to break at that speed. There were no warning lights, or symptoms. My vehicle seemed completely healthy.