Conversation so far:
When did Harry Houdini perform his buried alive stunt?
The first was in 1915.
Where did Harry Houdini perform his first buried alive stunt?
The first was near Santa Ana, California.
What did Harry Houdini's first buried alive stunt involve?
Harry Houdini was buried, without a casket, in a pit of earth six feet deep.

Question: How did Harry escape?
Self-contained rewrite: How did Harry Houdini escape his first buried alive stunt?