What is a potential danger of using a jack without jack stands?

Using a jack without jack stands poses a significant safety risk, primarily because of the potential for the vehicle to fall. When a jack is used to lift a vehicle, it provides temporary support while the vehicle is elevated. However, jacks are not designed to hold that weight indefinitely; they can fail due to various reasons such as mechanical failure, loss of hydraulic pressure, or shifting of the vehicle. Without jack stands to provide additional, stable support, there is a serious danger that the vehicle could suddenly drop, potentially causing severe injury to anyone near the vehicle or under it. This is why it is crucial always to employ jack stands alongside a jack when working underneath a vehicle to ensure safety and stability during repairs or maintenance.