Holy moley-- that's awful! I've never had that happen on grass (knock wood) although I worry about it on the hilly parts, but I've slipped under my CAR on a city street, sliding on the ice beneath the car when trying to de-ice the windows -- only my head was sticking out. Until I wriggled out of the way, I was terrified that another car would come and run over my head!
Yikes!
We obviously both live, ‘A Life of Danger’ but have lived to tell of it. ;)