What is the resolution of The Fall of the House of Usher by Edgar Allan Poe?

In "The Fall of the House of Usher," the house collapses into the tarn, a small lake, and it is implied that Roderick Usher and Madeline Usher die inside. The story ends with the narrator fleeing the scene as the house crumbles. It is left ambiguous whether the Usher siblings survive or perish in the collapse.