Urban legend has it that, anything combustible inside a safe, can cause an explosion with a torch?
Diamond cutting steel is S L O W!!!
If you happen to remember the Beagle Boys,’Paul Bunyan’ Machine, that might be the ticket? About the fifth photo down.
http://www.cbarks.dk/thebeagleboysstoriesa.htm
That might work.
Here’s 10 ways NOT to do it:
https://www.youtube.com/watch?list=PLaSFGn8np9Sevb4svwlddtj0sZ0qwAbC4&v=usFgj3cd0MI