It happened to my wife; one minute she's walking along the footpath, next she trips on an uneven edge and falls down, injures her ankle and is unable to stand. People who had been right behind her just walked on past, and people who appeared later, assumed she was drunk, drugged, or disabled.
Because she literally could not stand, she had to CRAWL to a nearby store, but of course the fact that she arrived on her knees, just made her look even more 'drunk, drugged, or disabled'.
After trying for several minutes to get someone to stop and listen, she was approached by a guy in the store, who didn't want to let her in, just wanted to move her on, but did finally agree to call someone for her.
The moral is: Don't fall down. And if you do, don't count on the kindness of strangers, there is no such thing any more.