Madelyn "Madie" Nicpon -- a junior on the Jumbos' lax squad -- was participating in a competitive eating event off-campus on Saturday when something went horribly wrong.

According to The Journal News ... authorities said Nicpon fell unconscious after choking, and was rushed to the hospital after first responders got to the scene.

Sadly, Nicpon passed away just a day later on Sunday.

"In the face of this painful loss," school officials said in a statement, "our hearts go out to Madie's family and friends."

Thousands of students came out to the campus to mourn the loss of Nicpon shortly after her death Sunday evening ... surrounding her jersey with candles and remembering her fondly.

"We are beyond heartbroken to share the news of the passing of junior Madie Nicpon -- 'Scooter,'" the Tufts lax team wrote on Instagram. "Scooter was a true friend and teammate. She truly valued her relationships with her teammates and coaches."

"Her reach was far beyond our team -- she was a true connector on campus and touched every single person she met."

They added, "We love you, Scooter. Keep dancing from above."

Nicpon had played in several games in her first two years for the Jumbos, and was expected to be a key contributor this season.