I made a video called “Tight Squeeze at Deep Cave” of cavers from the Greater Houston Grotto using the tiny side entrance to Deep Cave. The video has gone viral with currently just under 5 well over 6 million views on YouTube and countless other views pirated by viral content sites. It all appears to have started when someone posted a short clip on imgur.com, then moved to the front page of Reddit and onward.
Watch the video. Several people make it through the tiny sliver. For the record, the last person, Ryan Monjaras, made it through head first! Unfortunately, my video cut out right before his successful completion.

The clip featuring caver Chris Lafferty that sparked the viral activity.