The injured victim and his roommate locked themselves out of their apartment on Pico Boulevard and 6th Avenue.
The roommate decided to sleep in the hallway, but the man who ended up falling learned the perils of rappelling when he attempted to scale from the roof and enter through a window around 1:30 a.m.
"He tried to make a rope out of clothing and it didn't work", Sgt. Richard Estevez of the Los Angeles Police Department Wilshire Station.
He fell two stories and landed face-first on the sidewalk. Firefighters responded and transported him to a hospital. He is listed in critical condition, but is expected to survive.
CNS contributed to this report.