wow, that does suck. sorry for the loss. I wonder why it cracked. Did u recently bump into the tank or stand? I can only think that it cracked cause it wasnt sitting flat.
So sorry for your loss. I've been keeping tanks for over a decade but just last year got a pair if motoros. Stingrays are some of the most amazing aquatic creatures! Hope your insurance covers everything! How many other rays do you have?