There will be no triumphant comeback for the Auburn gymnast who broke both of her legs during a floor routine at the NCAA Regional Semifinals ... Samantha Cerio says she's retiring from the sport.
Cerio snapped both of her legs while trying to land a handspring double front on Friday -- she was stretchered off the mat with 2 air casts.
**WARNING -- THE VIDEO IS GNARLY AND GRAPHIC**
Auburn went on to advance to the Regional Final ... but Cero says Friday was her "my final night as a gymnast."
Cerio issued a statement saying, "After 18 years I am hanging up my grips and leaving the chalk behind.