Did hippies really vanish at Stonehenge?

With the most powerful symbols of ancient Britain, the megalithic site of Stonehenge, comes the mysterious event in 1971. A number of happy young people with some grass stayed for the night at Stonehenge, during a warm Summer in the era of glam rock. It was a place to enjoy a mystical night for these youngsters. The group consisted of three girls and two boys, named Julia Ashton, Wilma Rupert, Shary Wilson Jr, Lucas Addam and Danniel Wilson.
The Summer was proving "beautiful" at the ancient stones, they thought. They wanted to enjoy the stars and be close to the magnificent prehistoric structure. Then all were taken by surprise when a sudden violent storm happened after midnight. There was plenty of vivid streaks of lightning that disturbed even people everywhere in Salisbury. People in the location heard screams coming from Stonehenge, as lightning struck the megaliths.
Then the young campers at Stonehenge just disappeared during that very storm. Only their tents were found burnt from the lightning. So where did these young people go that night? Perhaps even more strange is why a diary belonging to one of the boys in the group, Danniel Addams, was found decades later just near the site. Pieces of paper was partially burnt, belonging to the young missing five people. According to the notes, the people wanted to have an adventure, although Wilma Rupert was described as feeling unnerved about it. There were notes that describe how Wilma dreamt that something scary might happen at Stonehenge.
Is this an urban legend, a piece of fiction or did it happen?
My conclusion: This sounds a bit too Hollywood for my liking, especially with the whole theme of American hippies taking a trip to England's ancient site, where they can chill out and get stoned. The entries in the half burnt diary about the girl Wilma's prophetic dream sounds just like a plot for a supernatural story. Stonehenge attracts millions of visitors every year, and there are tons of people who've spent the night there, before it was banned to do so. Lightning hits the stones in Summer storms, and the key paranormal of the place is a leyline. If that story of the vanishing hippies is true, the investigation into their disappearance was stopped, and it's likely more happened than what was revealed. If it did happen, then none of the families of the missing ever came forward to tell their story or appeal to the Press. Some conspiracy theorists claim it happened and the hippies vanished into a portal that was opened up by the storm, a bit like Dorothy from "Wizard of Oz" who disappeared when a storm struck her home. Perhaps it's just not a real event. My guess is as good as yours.
Info with diary of Danniel Addams at http://creepypasta.wikia.com/wiki/The_Disappearance_of_the_Stonehenge_Hippies
Howls ^^