Personally, I don't understand much about this matter, but I'm going to try my best at explaining who I think is to blame for this.
Firstly, some people beleive the government is to blame, as they should control what banks lend, give and keep. I partly agree with that point of view, as it is the governments duty to take care of their country and citizens, but essentialy I don't think the government is mostly to blame for this as adults aren't babies and should not expect the government to do everything for them, as it is very hard.
Next, I think it is also the bankers's fault for being too greedy for money instead of being mature and consider the consequences of lending money they are not 100% sure can be given back. I know it's their job, but they should also think about other people and how that can create a whole crisis.
Finally, I think the costumers are also very guilty for the sutuation. If they cannot give the money back they shouldn't ask for it in the first place, people have to be responsible and caring or if not there will be chaos. I know a lot of people have personal problems, but they should try harder, or maybe ask for less money.
In conclusion, I think this is all a matter of caring and thinking about how things you do can influence other peoples lifes. If people were more generous and caring for eachother, they would understand and try to think about others before taking action. That is honestly the only solution I see for financial crisis. Thinking about others, and to care about others, not only about yourself.