Frame failure sudden death? I had a serious accident, my fork suddenly snapped when riding.
I sent my bike for repair (to get a new fork installed) and the guys at the shop hammered the frame in place, as apparently the frame bent from the crash. 
Now after the very scary crash I had, I am wondering if I should even ride the bike in that condition? I know it is impossible to predict how much time will it take for it to fail, but other than checking very often if the area next to the bumps changes, what else can I do? I know that getting new pieces welded is not an option as it is hard to weld aluminum and it is probably less expensive or equally expensive just to get a new frame.
If an aluminium frame has to be bent back into alignment, it's trashed. Aluminium cannot be deformed without causing weakness in the material. 

If the bicycle repair shop literally hit the seat stays with a hammer near the dropouts to straighten the frame is probably weakened in those areas and is very likely unsafe. I personally would not ride that frame.

The bicycle repair shop should have told you the frame was un-repairable and not replaced the fork. Maybe they wanted to make some money of a repair job but I can't believe they passed up an opportunity to sell you a new bike.