Isobel Bowdery, 22, who survived the attack at the Bataclan concert center on Friday night, has penned a vivid account of the experience. (Courtesy of Facebook)

"You never think it will happen to you."

And so begins what may end up being the most harrowing, graphic and poignant account of what it was like to be trapped inside the Bataclan concert center on Friday night as gunmen slaughtered more than 80 helpless concert-goers in a matter of minutes.

That account was written by Isobel Bowdery, a 22-year-old South African who hid among the dead for over an hour as the nightmare unfolded around her. Her survivor story, recounted in grave detail, has been shared more than 600,000 times as of Sunday afternoon since she posted it on Facebook with a photo of her blood-stained shirt.

"It wasn't just a terrorist attack, it was a massacre," the recent University of Cape Town graduate writes. "Dozens of people were shot right in front of me. Pools of blood filled the floor. Cries of grown men who held their girlfriends dead bodies pierced the small music venue. Futures demolished, families heartbroken. in an instant. Shocked and alone, I pretended to be dead for over an hour, lying among people who could see their loved ones motionless."

[Horrified survivors recount Bataclan slaughter: ‘It looked like a battlefield’]

In a mere 15 minutes, the Bataclan, — a prized Parisian institution that has hosted luminaries like Edith Piaf, Nick Cave and Lou Reed over the years — was turned into a slaughterhouse, witnesses said.

Until gunfire erupted, as Bowdery points out, the night offered no hints of what was to come. The American rock band Eagles of Death Metal had been onstage for an hour when the gunmen emerged from behind the crowd. Muffled by the loud music and the excited crowd, the initial cracks of gunfire either went unnoticed or were misinterpreted.

"The atmosphere was so happy and everyone was dancing and smiling," Bowdery writes, "and then when the men came through the front entrance and began the shooting, we [naively] believed it was all part of the show."

Bowdery describes holding her breath, trying to remain motionless and avoid crying so that she didn't give "those men the fear they longed to see." She describes the gunmen circling the crowd "like vultures," an image that will haunt her the rest of her life, she writes.

"The way they [meticulously] aimed at shot people around the standing area i was in the centre of without any consideration for human life," she writes. "It didn't feel real. i expected any moment for someone to say it was just a nightmare."

Bowdery's writing emphasizes the senselessness of the violence, which claimed so many lives around her even as she managed to survive. But being a survivor, she points out, allows her to "shed light on the heroes."

"To the man who reassured me and put his life on line to try and cover my brain whilst i whimpered, to the couple whose last words of love kept me believing the good in the world, to the police who [succeeded] in rescuing hundreds of people, to the complete strangers who picked me up from the road and consoled me during the 45 minutes I truly believed the boy i loved was dead, to the injured man who i had mistaken for him and then on my recognition that he was not Amaury, held me and told me everything was going to be fine despite being all alone and scared himself, to the woman who opened her doors to the survivors, to the friend who offered me shelter and went out to buy new clothes so i wouldnt have to wear this blood stained top, to all of you who have sent caring messages of support — you make me believe this world has the potential to be better. to never let this happen again."

Lamenting the loss of so many innocent people, Bowdery adds that she "feels privileged" to have been present for their last breaths. Believing that her own life was about to be extinguished at the time, she assures her readers that the victims' last thoughts were not about "the animals who caused all this" but about the people they loved. She goes on to cite her own experience as an example:

"As i lay down in the blood of strangers and waiting for my bullet to end my mere 22 years, I envisioned every face that I have ever loved and whispered I love you, over and over again. reflecting on the highlights of my life. Wishing that those i love knew just how much, wishing that they knew that no matter what happened to me, to keep [believing] in the good in people. to not let those men win."

Bowdery's post has generated hundreds of comments from Facebook users who were moved by her writing.

"Beautiful words and thoughts," Facebook user Malindi Bryce wrote. "Your pain is mine and all of ours,"

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