LOL! Yeah, I was estimating slightly different numbers. Figured the panel was 2.5' x 6' and about 6" thick. Also figured it might be some kind of mortar mix instead of ordinary concrete. Just guessing though. I'm sure I'm wrong.
Looking at the picture of the piece that hit the ground its hard to tell what type of concrete was used.
The manufacturers of precast panels use all different kinds of concrete mixes.
I based my calculation on standard (150 lbs. per cubic foot) concrete.
Again,its hard to tell from looking at pictures,but it does look like the concrete was more of what we call a "sand mix".
It also looks like water may have gotten into the panel causing the concrete to deteriorate.Again,its hard to tell from a photograph.
If O.U. wants to fly me out,I'd be happy to look at the panels in person.