I've experienced something like an nde. There was no tunnel and no other beings though
I was 15 or 16 at the time. Me, my friend, my dad and friend's dad were going to this island to go fishing. We left early on a summer morning and arrived at the island at 9 in the morning. I had been wide awake since 6 o'clock but when we got to the apartment which we had reserved I got insanely tired and weak all of a sudden. I got barely to the sofa and managed to say to my friend that they should go without me because I was so tired. I felt like I was being forced or pushed to sleep and I didn't fight it, I quickly fell asleep.
The next thing I remember was that I was on a tropical volcanic island bare feet looking at seashells and crabs at the beach (a dream, obviously). Anyway, all the people I cared for, including my extended family, were residing at a cave next to a volcano. I was by myself at the beach. At some point I noticed a weird shimmer on the horizon and it made me feel strange. I tried to make sense of what the shimmer could be and the more I looked the more it started to look electrical. Like an "electric mirage" that ran across the horizon. I started to question whether this whole setting was real or not, I couldn't understand why the horizon would look electrical. Material reality doesn't behave like that, I thought. I didn't manage to become lucid because I soon realized that the shimmering was due to an approaching tsunami. The tidal wave stretched across the whole horizon and it looked like it could be a mile in height. I got horrified because I knew that all of us on the island were going to die. Regardless of this I started to run for the cave through the jungle in order to warn my friends and family. I kept thinking that maybe some of them might be able to climb the volcano high enough so that they wouldn't be washed away or get crushed by the wave. Everything felt extremely real and dire at this point. It was utter terror and desperation for me.
I didn't manage to get to the cave and the wave hit. So up to this point everything had been an imagination, I mean everything, including "my real life". After the wave hit in the dream there was nothing. There was no me, nothing visual apart from light blue clarity. There were no thoughts about or words for this clarity or this light blue "light space" and it wasn't seen by the eyes or experienced by the body. It wasn't seen by anyone particular. All this felt more real than anything but even the concept of realness wasn't there. It's impossible to describe this state. There's a recognition of pure recognition. It's like pure awareness with no attributes, being aware of itself/ myself as awareness/clarity. The attributes of clarity and color blue came only later when there was an apparent me again.
For whatever reason the world formed again. I have no idea why. First there was awareness aware of nothing and then there was spinning movement on top of which there started to be a visual sensation of the spinning and eventually there was the body inside the wave. I fell out from the wave, was in free fall for 10 seconds or so and hit the ocean surface. I actually kept sinking for a good while before I woke up on the sofa. I actually felt like I was born again but it wasn't unpleasant at all. I was feeling deeply blissful for a good couple of days. During this time everything felt clear, easy and my body felt 50 percent lighter than usual. I wasn't familiar with buddhism, hinduism, christianity or islam but after the experience I knew that the essence of this world is awareness. No question about it.
Abut 10 years later I read from the Tibetan Book of Living and Dying (by Sogial Rinpoche) that it is actually a dying process that I went through. It describes the pushing-to-sleep sensation, the mirage and the water element (page 255). I recommend checking the book out. There's also descriptions of the more classical near death experiences and about the different stages of dying.