The term "Saved by the Bell" has really morbid origins.
Back in the before times, people weren't great at telling if someone was actually dead, so a lot of people ended up being buried alive.
Because of that, often times today, when old coffins are opened up for whatever reason, they find scratch marks inside of it.
Old timey people were aware of this as well, so they created a method that gave non-deceased people a (small) chance to get rescued, by putting a bell on top of the grave stone, and connecting it the pinky toe with a piece of string. Thus, allowing the (likely soon to be suffocated) person a chance to ring the bell, and hope someone nearby hears it.
I always remember this, whenever I rewatch the Saved by the Bell series.