They got in the bottom of the safe...did the premise alarm system go off? Just curious how many folks have gun safes but, have no alarm system installed and working on the premises? PS-I don't sell alarm systems...not trying to sell one...Just curious...I mean assuming there were no FDIC would you put your money in a bank that had no alarm system but looked at ya and said but, we got a safe.
Take a 1/4" steel plate the same size as the bottom of your safe or at least wide enough to grap 3 floor joist below and bolt through steel plate with threaded rods (the thicker the better> Now if they try to tip it over then they'll have to snap 3 floor joists which on the vertical isn't easy. I also agree bolting to the wall is a good idea. The key is anything you can do to make it more difficult and slow them down works in your favor.