Fitzgerald was on the Morristown platform with the injury when responders arrived at the scene, just before 7:25 p.m., a spokesperson for NJ Transit said.
She saved her own life by pulling herself off the train tracks, onto the platform and screaming for help, according to a fundraiser set up to support Fitzgerald. Her supporters are calling it "The Miracle of Morristown."
Fitzgerald was then rushed to the hospital for surgery, although doctors had to amputate her leg.
"Extreme challenges exist for Lisa to return to the active and fun loving daughter, sister, and friend we all know and love," Samantha Fitzgerald, who organized the fundraiser, said. "Watching Lisa fearlessly smile through adversity inspires us all."
New Jersey Transit Police are leading the investigation. To view the fundraiser, click here.
Click here to follow Daily Voice Mountain Lakes and receive free news updates.