When you go sky-diving, there's that all-important business of making sure you don't slam into the ground, but you also have to make sure you don't slam into anything protruding out of it. This pair of urban wingsuit daredevils who dove into Rio de Janeiro came damn close to the latter when they zipped through a small gap between two skyscrapers.

All it takes is a little crosswind to screw everything up and ruin/end your life, but these guys made it out to dare another day and were nice enough to record it all with action cams. And all at 5:45 AM to avoid commercial air traffic. What have you done this morning? [Reddit]