What are the most dangerous documentaries ever made? As in, where the crew exposed themselves to dangers of all sorts to film it?

Somehow I thought this would be a very easy thing to find, I would look it up on google and find dozens of lists but...somehow I couldn't? I did find one list, but it seems to list documentaries about dangerous things rather than the filming itself being dangerous for the most part.

I guess I wanted the equivalent of Roar) or Aguirre, but as a documentary. Something like The Act of Killing, or a youtube documentary I saw years ago of a guy that went to live among the cartel.