How did the hanger bend and derailleur crack? There must have been some sort of impact to do that. Highly unusual for that to happen in normal riding without some sort of direct force, such as leaning it against something when stopped, pushed up against the wall or seat if packed in a suv or minivan, etc...
I always carry an extra derailleur hanger just in case something like this happens. Not much you can do about the derailleur though.