Not that they happen, but that's they're "other worldly".
I saw a documentary about a year ago where a British (?) scientist "died" and recorded his experiences using EEGs, PET scanners, etc. What he saw was nothing more than oxygen deprivation of the brain.
My own Mother died 5 months ago. The cause of death was sepsis after her intestines exploded and the infection was everywhere in her abdominal cavity. I saw her a day before her surgery (last time she was able to speak) and she talked about the beautiful garden she was seeing (she actually had a view of the HVAC of the hospital roof) and other things. I now believe it was the toxic poisons making her hallucinate.
So no, that's the bummer about science - it takes away the magic.