Tragic. This Guy Was Working On This Sculpture For 5 Years (6 pics)

So we are supposed to guess what happened?

The source says what happened, it was a clay sculpture that was moulded.

It appears the source and this post are misleading. Very misleading.

It's a clay form that was used to make a mold. The clay form can then be destroyed and reused. The mold is then used to cast the final, more permanent, form.

The sculpting of the marble is done with a pantograph or pointing machine that traces the contours run by craftsmen, not the artist. This has been done for centuries.
Many works are done as miniatures in clay and enlarged with these devices. A clay model this size is unusual.