I was trying to get my jack under the car without kneeling and I didn’t want to have my pants wet all day in the clinic. I finally got my jack under the car next to her jack and raised the car enough to put the old tire back on. I had two of the lug nuts halfway on when her jack buckled and collapsed and the car lurched forward. That put all the weight of the car on my jack and as the car went forward, my jack collapsed and folded and the old tire was barely on the car. It was plain to see there was no way we were going to get her tire changed.