THE dust-covered 9/11 survivor whose haunting image became an emblem of the tragedy has died after a yearlong battle with stomach cancer, her family members announced on Facebook.

“I can’t believe my sister is gone,” Michael Borders wrote of his sister, Marcy Borders, late Monday night.

Marcy was dubbed the “Dust Lady” after a photographer snapped a now iconic photograph of her caked with ash just after the World Trade Center attacks.

John Borde called his cousin a “hero,” saying she “unfortunately succumbed to the diseases that has ridden her body since 9/11.”

“In addition to losing so many friends, coworkers, and colleagues on and after that tragic day … The pains from yesteryear has found a way to resurface,” he added.

Borders was just a month into her new bank job on September 11, 2001, when a plane slammed into the north tower where she worked. Instead of staying at her desk, as her boss had ordered, she fled from the building and into a street scattered with wounded workers.

A stranger pulled her into a building lobby just as the north tower collapsed — and it was then that a photographer captured her terrified face in a famous photo that has since been seen around the world.

Borders’ life spiraled downward in the years after the attacks, as she battled severe depression and became addicted to crack cocaine.

“I didn’t do a day’s work in nearly 10 years, and by 2011 I was a complete mess,” she told The Post in 2011. “Every time I saw an aircraft, I panicked.”

But Borders, after losing custody of her two kids, checked into rehab in April 2011, and remained sober since, she told The Jersey Journal in November.

She also announced that she’d been diagnosed with stomach cancer in August 2014 and had undergone chemotherapy. She added that she was scheduled to undergo surgery in December, followed by radiation and more chemotherapy.

The attacks ever on her mind, Borders wondered if her illness could be related to what she endured on September 11.

“I’m saying to myself ‘Did this thing ignite cancer cells in me?’ ” she told The Jersey Journal.

“I definitely believe it because I haven’t had any illnesses. I don’t have high blood pressure . . . high cholesterol, diabetes.”