Explain who was responsible for the real estate crisis of 2008-2009–borrowers, lenders, sellers, real estate developers, the federal government. Why?

Please watch the movie “The Big Short”
after watching the movie answer the following question:

Explain who was responsible for the real estate crisis of 2008-2009–borrowers, lenders, sellers, real estate developers, the federal government. Why? Please cite and use specific quotes/examples from the movie. If you use any material outside of the movie, be sure to cite the source and explain how it supports your views/ reasoning of the parties responsible for the crisis.