The Mystery of the Stolen Statue (Third-grade Detectives)

The Third-Grade Detectives are looking forward to their field trip to a local art museum, where a priceless fifteenth-century statue of Joan of Arc is on loan from a Paris museum. But when they arrive, they discover that the statue has been stolen!
The police quickly find the statue -- smashed into pieces and thrown in a Dumpster. Why would someone steal the statue only to destroy it? It looks like a new case for the Third-Grade Detectives -- even if the museum director doesn't seem to want their help.