In 2012, Choi Gap-bok escaped from prison by squeezing his body through a 5.9″ tall and 17.7″ wide food slot when the guards were sleeping. He is a yoga practitioner and applied skin ointment to his body in order to slip out. – WTF Fun Facts
Source: https://www.huffpost.com/entry/choi-gap-bok-prison-escape_n_1919866
