Can it really be 15 years since 9/11?

On Sunday, we honor those who lost their lives that terrible morning. Meanwhile, many surviving first responders continue to suffer with illnesses linked to Ground Zero exposure.

But all the victims and survivors weren’t in the towers. And all weren’t adults.

Helaina Hovitz was 12 years old when she stepped out of IS 89, just blocks from the WTC, into a living hell.

Her mom worked at Rockefeller Center and dad in Staten Island, and neither could make it downtown to get her. When her neighbor Ann dashed in to pick up her son, Helaina begged, “Take me with you, please.”

The three bolted through the school doors to blinding smoke, falling bodies, and crumbling towers, as Ann told the kids to cover their faces and run for their lives.

With crews digging through rubble and the air still toxic, IS 89 was no longer safe. When Helaina and her friends were shipped to a school uptown, its students couldn’t understand why planes flying overhead made their new classmates so jumpy. One day, a passing truck loudly backfired, and the IS 89 group ran or hit the ground. “The other kids just stared at us like we were crazy,” Hovitz recalls.

The reporters soon found the displaced kids. “Did you see people jumping?” they’d demand of the traumatized children, waving microphones at them.

As she moved through her teens, Hovitz tried to muffle the panicked voices in her head with drugs and alcohol, drifting into abusive relationships and paranoia. Eventually, she was diagnosed with post-traumatic stress disorder.

With help and resilience, Hovitz eventually dug her way out, and became a journalist highlighting positive stories. She recently launched a news service called Headlines for the Hopeful, and her book, “After 9/11: One Girl’s Journey Through Darkness to a New Beginning,” describes her decade-long spiral into addiction and battle to heal.

Although Hovitz seems to have emerged on the other side intact, her PTSD is triggered in times of stress.

“I know that as much as ‘fear’ can stand for ‘false evidence appearing real,’ ” she says, “it can also stand for ‘face everything and recover.’ ”

Playwright Mike Vogel blogs at newyorkgritty.net.