This happened a while ago:
I was busking in the Public Garden, as is my wont, when a man nearby collapsed to the ground. Before I could dig out my phone to call 911, one or two other people already had. The guy was conscious and trying to get up, but he was clearly disoriented, so a couple of nice motherly types were insisting that he lie down and wait for the ambulance, while three or four others stood around to kind of protect him from being stepped on, since he was in the middle of the sidewalk near an entrance where there's a lot of foot traffic.
What particularly impressed me about this incident was that the man was the type who makes a living from the garbage bag of cans he was carrying when this happened, and all these people stopped to help him anyway and make sure he was OK.
The EMTs stashed the bag of cans in the shrubbery; I don't suppose taking it with them would have been practical.