Is 1000lbs too much weight on a typical floor?
Why would you, or anybody in their right mind pile it all in one spot, then ask?
Do you play Russian Roulette? What would it have taken to spread out the load a little?
As to the load bearing capability of Dri-Core, that has absolutely nothing to do with this issue. Dry core is placed with the plastic side down on concrete and is continuously supported. when it is properly installed. So how does that apply to a pile of weight point loaded over 4 square feet on a frame supported floor???
" A lot of men build things, and a lot of things fall down "