There are some things that cannot be explained - by science or any other means. Mary Saner takes a close look at one of these inexplicable and astonishing phenomena - the near-death experience.

As many as 13 million people in the United States claim to have had what's known as a near-death experience. They were critically close to death ? or were actually declared clinically dead - they weren't breathing, and had no heartbeat - but then, they regained consciousness. Their accounts of what happened during that event are strikingly similar.

"One of the characteristics is being out of body, a viewing of their body from another perspective. In medical situations, they perhaps find themselves floating on the ceiling looking back down on their body on the operating table and seeing the doctors and nurses working on them," explains William Taylor, 61, who had a near-death experience that he says dramatically changed his life.

"In 1979 I had a cardiac arrest and I coded three times [coded means that your heart stops or your breathing stops.] I was revived three times. The essence of what I experienced was I suddenly found myself way out in space, and I could look back and see how everything is connected to everything else," he recalls. "There's just a warmth. I didn't have an extremely bright light, but I could see light in everything. I still could experience and think, 'Wow, I'm still here. I'm still separate and I can still think.'"

Mr. Taylor says he made the decision to live.

"There was a very powerful being there and this being said, 'It's your choice.' My mother and my father were alive and they were at the hospital, and this being told me, 'Before you make this choice,' (I'm in spirit form here )'put your hand on your mother's heart and also put your hand on my heart,'" he recalls. "And I think when I did that, I felt her pain would I have died - would I not have come back."

But, like many who encounter near-death, Mr. Taylor says it was difficult to talk about his experience afterwards, because no one believed him.

"I told my cardiologist and he said that we really can't explain this and there's no reason that we need to discuss it any further. And my family was not real happy to hear about it either," he says. "Since then, reading some of the literature, it's often times most difficult to talk about it with family and close friends. A total stranger is often times more easy to converse with, because a family, I guess they see you in a particular light and they expect you to behave in a certain way."

Fourteen years after his heart attack, William Taylor joined the International Association of Near-Death Studies. IANDS offers information and a forum for people to talk and listen.

"Welcome everybody. This is the Maryland Chapter of the International Association of Near-Death Studies. Today, we thought we'd look at a video and then open for discussion later on," says the host.

After watching the video featuring nurse and IANDS Board member, Debbie James, the 11 men and women seated around the long table begin to talk.

"I have not shared my experiences much," admits one woman. "I haven't. I'm afraid of giving them up."

"My experience was so precious to me that it was only when I started coming here about two years ago that I told my story," says Larry Bott, 80. "My wife asked me 'why are you going to this group?' And I said, 'Well, you know, I had that experience in India.' She said, 'I don't know what you're talking about' and evidently I'd never told her about it."

Mr. Bott comes to many IANDS meetings. At this one, he relates his near-death experience 20 years ago.

"I was trekking in the Western Himalayas and went back to New Delhi, wandered around the streets of Old Delhi, got very sick and was in my hotel room and I started experiencing music," he explains. "It sounded like a choir".

Then, he says, he saw something that was vivid and unforgettable.

"I watched from the corner of my hotel room at myself at one point. The manager of the hotel had come in the room and was shaking me, and it was so disturbing," he recalls. "I was enjoying myself so thoroughly. He shook me, and I spoke to him and said, 'why are you shaking me?' I looked down on the bed and said, 'I'm just fine.'" But Mr. Bott was not fine. He had lost 20 kilos from dehydration and was suffering from bacillary dysentery. He was brought to the intensive care unit at a hospital in New Delhi and eventually recovered. Mr. Bott says he is enjoying life, and has no fear of death. Many in the religious and medical communities are unsure of what the near-death experience means.

But not David LaMotte. "Through 25 years now of my studies, I think this is the most exciting and important revelation, if you want to call it that, that has ever come to earth," he says.

The Protestant minister has spoken with about a dozen people who've had a near-death experience and has read accounts of hundreds of others. He says near-death experience has extraordinary importance for spiritual thought.

"It has meaning for everyone, everywhere, in every way possible," he says. "This particular occasion of near-death experience comes to Christians, Jews, Muslims, Buddhists, Hindus, pure atheists."

Mr. LaMotte has been studying near-death experience to help him respond to his parishioners' questions and fears about death. And, he says, from what he's seen and learned, many of those who've experienced near-death view life differently than the rest of us.

"They are open spiritually to practically anything that is good. Love and knowledge. And they believe that all of us are related, and that life is beautiful, no matter what part of the world you're in, no matter what race or religion - we're all related in the beauty and love of the Almighty," he says. "I don't know what this is, and I would think it may be actually something going wrong because of lack of blood flow to certain parts of your brain," says Cardiologist George Young, a skeptic. Many near death experiences occur during cardiac arrest, and Dr. Young says the body's response to a heart attack could be responsible for some of the common phenomena of near-death experiences. For example, the bright light many people claim to see could involve brain cells firing off as they die.

"You can actually see that with an MRI," he explains. [You mean the cells firing off?] Willy- nilly, all over the place, and you might be able to get from the optic neurons a very big firing off. It's like a light bulb that pops when it burns out. It could be that phenomenon."

He says the euphoria that many claim to feel during near death might simply be the effect of pain killing endorphins being released in the brain. But for the other common symptoms - the sense of passing through a tunnel, floating outside the body, meeting deceased relatives - no medical explanations have been offered.

Many scientific studies are under way to what happens during near-death, and in the meantime, William Taylor has a message for those who haven't experienced it.

"It would be good if people could retain an open mind and not put things down just because they don't understand it or science can't explain it," he says. "Remain open to it a little bit. Perhaps it is possible. Maybe there really is a heaven. Maybe that's really where we go. Maybe we don't really die. Just think about some of that."

The International Association of Near Death Studies has about 1,000 members around the world. It offers information and resources about the experience on its website: