Not the fault of the kid.
Items like this are termed, “an attractive nuisance”.
It is the museum’s fault for not securing it, either physically or with some barrier. Things this heavy are a danger to the public and young children specifically.
That’s what I was thinking. Why wasn’t something so valuable and fragile secured better? Seems like negligent on three part of the facility. Sheesh, anyone could have bumped it, public, maintenance/ janitorial staff...