Is Usher responsible for the death of his sister and the collapse of his home?

Usher is responsible for the condition of his home..... he and Madeline allowed it to fall apart. His sister's death is a little more questionable. We can infer that Madeline was catatonic when placed in the coffin..... this, in addition to her having to claw her way out before attacking her brother is likely the cause of her death.