Roughly three dozen members of a University of Michigan sorority "became ill over the weekend from an apparent widespread case of food poisoning."  The pathogen causing the outbreak has not yet been identified.   It appears that many of the women fell ill in a very similar time frame:

When fire crews and paramedics responded Saturday they found dozens of women vomiting, eight of which were taken to a hospital for care.

The sudden and consistent onset of symptoms in the sorority members may indicate that the pathogen involved is Staphylococcus aureus.  According to the FDA:

The onset of symptoms in staphylococcal food poisoning is usually rapid and in many cases acute, depending on individual susceptibility to the toxin, the amount of contaminated food eaten, the amount of toxin in the food ingested, and the general health of the victim. The most common symptoms are nausea, vomiting, retching, abdominal cramping, and prostration. Some individuals may not always demonstrate all the symptoms associated with the illness. In more severe cases, headache, muscle cramping, and transient changes in blood pressure and pulse rate may occur. Recovery generally takes two days, However, it us not unusual for complete recovery to take three days and sometimes longer in severe cases.

Local health officials are investigating.