Angle grinder and a shit load of disks will usually be sufficient. Takes a while, but unless they have James Bond style poison gas / acid / explosives etc embedded in the safe enclosure you will eventually make it through.
Examples:
Sewn up - https://www.thesun.co.uk/news/3319119/man-carves-open-throat...
Grinding wheel still in the face - https://www.reddit.com/r/Welding/comments/1sq6v7/wear_your_f...