wild guest like this, can it just be manufacturing defect. Seen how clean the break is, i see happen when i was working at mcdonald, a guy took the grill scraper that was in metal, he hit the frige not very hard with the scraper and it broke clean in half like in the pic. All so happened to my punching bag when some one kicked it and one of the hooks broke clean.
might be the reason why most essential metal structures and stress tested befor used