CJD
Yoda

Online
The main cap went after the crank died because of the severe twist it was subjected to. Note the break started right along the journal corner...if you had a close up, I have no doubt you would see the fatigue beach marks fanning out from a point along the journal corner. Also, that is a steel part, as a cast crank would have a larger, dark, crystalline area at the break, instead of the shiny surface from extensive rubbing as the crack grew.