How does Heather die in the Blair Witch Project?

Answer 1

heather starts screaming and then you see mike standing in the corner because that's what the old man made the children do when he killed them and then you see mikes feet hanging above the ground and there he died!

Answer 2

We never find out exactly. In the last scene, she and Mike are looking for Josh because they hear him screaming again in the middle of the night. They find that house in the middle of the woods (the house of that crazy guy who killed all the children), and they think they hear Josh screaming inside. They run through the house, looking for Josh, and Mike thinks he hears him in the basement.

Mike runs down to the basement, then there's a big thud,and Mike's camera falls to the floor and continues taping by itself. Then Heather runs down to the basement, and there's a thud, and then her camera falls to the floor and continues taping by itself. But just before Heather's camera falls, we see Mike standing in the corner, facing the wall.

If you recall, when the trio were doing interviews with the townspeople, at the beginning of the film, one of the men they interviewed told them about the children the old crazy guy had murdered. He said that the guy took the children down to the basement to kill them in pairs. He would have one of them stand facing into the corner while he killed the first one, because he "couldn't take the eyes on him," he couldn't stand the eyes of the other child watching him while he killed the first. So, we never find out exactly what happens, but presumably Mike and Heather are killed the same way the children were (however that was).