How often can a real death occur when someone is dreaming? I read this article about these 2 perfectly healthy Asian men dying after they went to sleep. So here's what happened. Apparently, these guys were victims of torture or something in Korea so they refused to sleep. Then one night they do sleep, they die. I heard this is how the idea of Freddy Kruger was created and obviously he isn't real but real life death from sleeping is?

No I'm not talking about dying in dreams but dying in real life from having a nightmare. What are your thoughts on this?