What’s the worst reaction you ever have had consuming food, vaccine, medicine and or a drug?

In college, our fraternity had a banquet at a nice big restaurant in Atlanta. That night, at least 50 of us were violently ill, keeping the fraternity house bathrooms and even the bushes outdoors busy with vomiting young men. The restaurant denied it was their fault, but it was the only place all of us had eaten anything. I believe we reached a settlement in which they paid half of our expenses. Most of us were in class the next day, but not feeling good. I don't recall what item of food was the culprit.