A little boy was helping his father work on a car at their home in Sugar City, Idaho when the Toyota Prius slipped from the jack.
JT Parker, 8, saw the 1400kg car crush father Stephen Parker, which broke 13 of his ribs making it excruciating to breathe on the hot July day.
The 22kg boy adjusted the jack and started jumping up and down on the handle for 15 minutes to lift the car.
JT told East Idaho News: "It was scary, and I didn't think that I could jack the car up, but I just kept on trying."