You better get some rubber grips for the handle. If you have even the slightest bit of moisture on your finger tips you will have a tough time opening this safe. Mine is locked until my hands are less damp. Not wet, damp. Might try putting a pair of pliers with vice grips to open it or getting some sort of friction pads to put on it.
Thing is 30 times lighter then the safer I replaced it with so better mount it. Forget fires or water, this wont handle it.