Originally Posted by Moonmaiden23
I think Leopold was driving very recklessly, as he was known to do and as he continued to do for much of the rest of his life.
This is your own interpretation.
According to reports the following happened:
Leopold was at the wheel while Astrid was holding a map. When Astrid pointed out something on the map, Leopold leaned over to look at it and took his eyes off the road. The car hit a large rock lining the road and got off the road, sliding down the slope towards the lake. Leopold lost control over the car and Astrid was flung out off it, landing with her head against a tree. She was killed instantly.