Legal Question in Criminal Law in Georgia

First of all, obviously you did not provide a single detail about what security they had or did not have so I am not sure how you expect a meaningful answer. Beyond that, one person is generally not liable for the crimes of another person. Obviously, banks are not going to be required to post armed guards at every point of the building, exterior and the parking lots to prevent every possible scenario. So, no.

Contrary to Scott's post, the bank MAY be liable (probably not, but it depends on the facts). See a lawyer and discuss the details.

You absolutely can sue the bank. You can sue anyone at anytime for anything. Are you going to find an attorney who knows what he/she is doing to take on the case? That is the better question. Are you going to survive summary judgment? That is a better question. Wells Fargo does not guarantee your safety when you engage in busienss at their establishment. If there have been prior robberies similar to yours, and they have taken no measures to try and reduce the incidents of armed robbery, then you may recover some money. If this is the first time that someone has been robbed at the ATM, or if you refuse to be aware of your surroundings wen you were robbed, then you eat the financial and emotional loss.