Why did you have to call 911? Like what was the emergency?
As a general rule for most dorms (and other similar housing arrangements, like assisted living for the elderly), if a resident asks you to call 911, you--assuming you're the caregiver or someone in authority, like SilverEagle was in that situation--are legally obligated to call 911 for them. At least that's how it is in my state.
Since it was a dorm, well...could have been anything, really.

Somebody drank too much, passed out and hit their head on something; your roommate turns out to be a sociopath*; domestic violence; somebody OD'd on something, whatever.
* Cool story, sis time: one of the few times I've dialed 911 in my life was for an incident like this. Guy I knew had a roommate who was a straight up sociopath; one time it got so bad he wound up crashing with my roommate and I while I dialed 911 and the dorm's residence director for assistance (at 2AM, no less). Good times!
I'm pretty sure that sociopath was the same one who liked to get drunk and literally destroy the bathrooms and smear bodily fluids all over the building elevator (don't ask, you DO NOT want to know) on the weekends, now that I think of it.
...College is fun, kids! :wacko: