That is so sad.
You just can't have anything of value unguarded any more.
I suspect an inside job though. I'd start by rounding up the usual suspects.
I'm sure that if you call your local police department, they'll be more than happy to send out their CSI-style crime scene unit and process it for all physical evidence. I'm reasonably sure that there will be DNA left on the bricks. Be sure to ask them to use their alternative light
source for fingerprints and body fluids before they dust anything for fingerprints.