If it's a real safe, most likely. My "safe" is, like probably most here, a 600 lb. RSC. An actual safe is far heavier.^^^ 500 lb/sf is a lot. Typical wood framed flooring is designed for 40 lb/sf. (distributed uniformly). If your safe is approx. 2-1/2' x 3' that's 7.5 sf --> 3750 lb. That's an almost 2 ton load on a small area. If it's on a concrete slab, it's probably not a problem. But 500 lb/sf doesn't sound right. Are you sure it's that heavy?