Cracked and sagging floor

I replaced the carpets years ago and there definitely wasn't any of those reinforcements on the floor. I was just looking and the passenger side is starting to crack around the same hole. Looks like I'll have to fab up some for both sides. If the floors crack like an eggshell with my 175 lbs. boy I'm in trouble:D

Remember those floors are like 50 years old and have seen some use. Cracks in sheet metal happens. It’s what you do with them is what counts.