The whole reason this happened is because the bank was giving away money to easily and they knew people wouldn't be able to pay back what they took. To put it in a simpler form they made a big risk. Was it because they were careless? Some people might think it was the banks fault but in my opinion I think that it's everyone's fault.
Firstly, it began with the bank lending too much money to lots of people even though they knew it was a risk. It was a risk since they actually knew that giving away to much money would cause a crisis like this and that people wouldn't be able to pay back the banks. That is one of the reasons it is the banks fault.
Now that the banks had a less amount of money people thought that they coudn't trust their money with the bank so they took it away. That is why it is the people's fault. Since the banks had ran out of money the government had to rescue them. If the people hadn't taken away their money the government wouldn't have needed to rescue the bank.
The bank still wasn't able to lend as much to people and to businesses. That meant people lost their jobs. Some were the ones who helped create this promlem and some were just innocent people. This also led to problems like not being able to pay for bills and rents. People might have been evicted as well. This situation caused a lot of problems even for the people who weren't involved in it.
Because everyone did their own part of the problem it's each and everyone's fault. This does not involve the people who didn't do anything to help increase the crisis.