Incorrect placement of your safe, especially a tall unit, can cause a real safety issue.
Many years ago a new employee set up a 700# gun safe in our showroom on pieces of 4” x 4” wood. The wood was pushed back about 5” from the front edge, making the safe unstable. That night I was working alone and opened the door of that safe to check it out. It fell forward as the weight of the overhanging door moved the center of gravity beyond the wood. It caught me by surprise and I did not react quickly enough. The outside corner of the door hit the floor hard enough that the door was pushed up and off the hinge pins so that it fell on me knocking me to the ground. With a major effort I pushed the door aside and off of me, but then the safe body came down with even more force. Luckily there were no injuries. I was able to get out from under it rather than be trapped until the next day, but it could have literally killed me.
A recent customer brought this incident to mind. He bought a high-security plate steel safe which measured 72”h x 40”w and weighted 2700#. He drove it home himself on a flatbed and was able to lower it into his basement while remodeling his home. Woodworking is his hobby so he built it into place in a cabinet with a deep toe-kick area. Guess what happened when he opened the door!! He was extremely fortunate because the door was at exactly 90 degrees when the door hit the floor, and the hinges stayed intact. Because the center of gravity was very close to the edge of the support he was able to push it back into place. He could easily have been crushed.
Tall, shallow gun safes may be especially unstable. Putting them on a thick carpet makes matters worse and they can fall forward when the door is opened. Without thinking about it, a minor action like resting your hand on the open door can make the difference that causes an accident. It is best to bolt these safes down to the floor for stability. Adding lots of weight inside (say, 200# of silver) will help, too.
When placing a safe make sure it is resting on solid support right out to the front edge of the safe, and bolt it down if there is any chance it is not stable.