Oh My...Just saw this thread, and it does sound a lot like panleukopenia/distemper. The vomiting bile, and high temps are a few of the symptoms. Is there diarrhea as well? Usually it hits hard and fast like you've described, and it's been very prevalent this year. Michigan was hit hard and one area lost over 800 cats and kittens due to an outbreak. I'm glad you're helping control the colony there, but also hoping you aren't going to burn out before you really get going. Stock up on bleach and wash down everything with a mixture of bleach and water. Right now it's the only thing I can think of that would cause so many to just drop like that. Keep us posted, and hang in there.
edit..Feline Infectious Enteritis...same as panleukopenia. Horrible virus that really can depress a person fast.