The chilling 9/11 secret that will leave you wondering 'why'

A haunting note has been shared online on the anniversary of the September 11 terrorist attacks.

The note that reads ‘Everyone who knew me before 9/11 believes I’m dead’, was first sent to PostSecret about five years ago and has been posted again on Twitter.

And by the looks of most peoples’ comments, the words on the card continue to leave them asking questions.

PostSecret is an ongoing community art project where people mail in their secrets anonymously on one side of a postcard.

“This is the PostSecret I find the most... Creepy is the wrong word, but the one that sticks with me the most. If it's true, someone started a whole new life away from everyone they ever knew,” one person commented online.

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Desperate for answers the postcard even had a dedicated website and Facebook page, but the site has since been deleted.

The website claimed to follow “the story of three friends who went in search of the PostSecret which read, ‘Everyone who knew me before 9/11 believes I’m dead’, and what they found.”

As America, and the world, remembers September 11, 2001, people on Twitter said they were still haunted by this one note.

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