The bash went down on Saturday night in a residence hall on the Purdue campus in West Lafayette, Indiana ... and once University officials found out about the party, they took action immediately.

All 13 student-athletes -- along with one student who isn't an athlete -- must be OUT of their dorms by Wednesday to begin serving their suspension.

The school says the actions of the students violate the "Protect Purdue Pledge" -- which is basically a new set of rules to minimize the spread of COVID-19 ... wear masks, social distance, wash hands, etc.

The school has not identified the suspended athletes by name -- or even said which sport they play.

In fact, all Purdue has really said is that they're all "out-of-season" athletes -- which means they're not part of a program that competes in the Fall.

The University issued a statement to ESPN saying, "While this is an unfortunate occurrence, we hope it's instructive for all Boilermaker students and reinforces the importance of protecting everyone on campus during this time."

As for the athletes, Purdue is expecting them to appeal -- and officials say they will handle that process "expeditiously."

"Each case will be resolved in a manner that meets the objectives of (1) protecting the health & safety of the campus community and (2) educating students on how to effectively adhere to the Protect Purdue Pledge."