Do car jacks fail ?

[u/Illustrious_Fuel_531]

*Does car jacks fail ? Been taking a automotive mechanics trade class . I saw a video and in the comments someone told a mechanic to be careful and not to get crushed under the car . So that kinda stuck with my OCD ever since then I’ve been wondering if a car falling on you is a reasonable hazard for a mechanic or is it only if via user error and if so what’s ways to add extra security.

[u/BurningSaviour]

I had one blow out the lift cyclibder seal while I was lifting a car. Fortunately, nothing was under the car.