When I had my own club in Bossier City, LA in the late 80s-early 90s, we had seats for only 55 people, and a really small dance floor. We routinely had 75 to 100 people in there and the Fire Marshall looked the other way.
One Saturday night at the peak of the evening an elderly guy had a heart attack on the dance foor.
We turned on the overhead lights and a customer started giving him mouth-to-mouth. The emegency unit from the FD was there in less than three minutes, and they shocked the guy several times and finally got him to come around. By the time they moved him to the hospital an hour had passed. Not one customer left. It so happened the guy from the Fire Dept. in charge of occupancy came in to see what was happening.
Afterward he told me I needed to count my customers to be sure I wasn't over the limit.
There were at least 100 there and he knew that! I was told it was the best show we ever had.
DonM
P.S. The guy that had the heart attack fully recovered.