Conversation so far:
When was Harry Houdini buried alive?
Harry Houdini performed at least three variations on a buried alive stunt during his career. The first was near Santa Ana, California in 1915, and it almost cost Houdini his life.
What was so life threatening about Houdini's buried alive stunt?
Houdini wrote in his diary that the buried alive escape was very dangerous and that the weight of the earth is killing.“

Question: How did he escape?
Self-contained rewrite: How did Harry Houdini escape being buried alive?