How suicidal 9/11 cop was saved by ‘angel’ on Christmas Eve in incredible story that echoes It’s A Wonderful Life

However, apparently undeterred by Simpson's attempts to shrug her off, the woman turned to him and asked "Isn't it pretty?", gesturing towards the snow-covered trees flashing past their window.

Simpson didn't respond. But on and on the woman still mused, telling him how much she loved the holidays and how beautiful New York City looks at this time of year.

THE COMPASSIONATE STRANGER

Growing angrier with each passing remark, Simpson said he considered throwing himself out of the train window rather than endure the woman's jovial ramblings for the entirety of the two-and-a-half-hour journey ahead.

The woman would again attempt to coax Simpson out of his silence, asking him what he liked most about the city. Simpson said the rudeness of his response shocked even him.

“I love anonymity,” he snapped back at the woman.

“I love that in a city with over 8 million people, I can go for days without talking to a soul and not feel as though I missed out on a single thing. However, the thing I love most about New York City is being left alone.”

Startled, the woman stared back at Simpson and was noticeably upset.

Simpson said he was immediately overcome with feelings of guilt and shame for speaking to the woman the way he just had.

He issued a hasty apology to the woman and, to his relief, she accepted it.

She then introduced herself to him as Erin, a grandmother from Saratoga.

Erin told Simpson about how she had lost her husband, a doctor, a few years earlier.

She was once a doctor too, she told him, though gave up practicing when her children were born.

A LENDED EAR

Slowly, over the course of the journey, Erin prized out information from Simpson about his own life.

With it having been so long since he had spoken with anyone about anything that mattered, Simpson said he periodically choked up as he talked with Erin, moved by her kindness.

He told the stranger all about his childhood in Brooklyn, spent with his father James, an NYPD detective, and his brother, and how he lost his mother, an alcoholic, when he was just seven years old.

He also recounted the 1993 incident that would leave him disabled.

Simpson had been on patrol for Midtown’s Third Division along 12th Avenue when he approached two hooded men who were acting suspiciously. One of the men pulled out a gun, and as Simpson lunged for the weapon it went off, shattering his knuckles and leaving him permanently injured.

He also told the woman of his battle with alcoholism; how he awoke from a drunken slumber to find the Twin Towers had collapsed; how he attended the funerals of 23 fallen officers he called friends whose lives were claimed in attacks.

Simpson said tears pooled in his eyes when the woman would occasionally touch his arm, in a compassionate bid to comfort him.

Shortly before the train arrived in Albany, the woman excused herself. She returned a few moments later with a pink slip of paper that she handed to Simpson.

“I don’t know where you’re headed,” she told him, “but when you get there, read this.”

The pair shared a hug before Erin walked away.

Simpson continued on with his plan, taking a taxi to Black Mountain, where he walked along the two-and-a-half-mile trail, reflecting on his life.

At the summit, he took out his father’s Bible from his pocket. A small scrap of paper flew out from it, on which his dad had marked his favorite passage: Corinthians 10:13.

'LIFE IS A GIFT'

Simpson thought the note was strange. 10:13, he remembered, was police code for an officer in need of assistance.

He read the passage and absorbed its messages of salvation, no longer feeling alone.

Simpson then took out the pink slip of paper Erin had handed to him.

On it, she had written: "Dean. Life is a gift meant to be shared. Don’t ever give up hope! Merry Christmas, Erin."

He stared down at the kind stranger's words and felt a shift within himself - which, on reflection, he would deem to be a renewed sense of purpose.

Simpson emptied the chamber of his father's gun and threw it off the mountain.

He then headed back down the trail with Erin's words still ringing in his ears.

She was right, he thought: he had been given a gift and it was time for him to share it.

In the two years that followed, Simpson would give up alcohol and relocate to Delray Beach, Florida, where he threw himself into volunteer work to help traumatized veterans rebuild their lives.

In 2010 he met the love of his life and married her four years later.

IT'S A WONDERFUL LIFE

Simpson hasn't crossed paths with Erin since, though he says he still thinks of her often and the kindness she showed him.

He now keeps her note and his father's bible on his top dresser, reading them both from time to time.

“Angels are around us,” he writes in his book. "People talk about acts of kindness. We may not realize how many of them are bestowed on us every day.”

Simpson's remarkable story bears a striking resemblance to the 1947 film, It's A Wonderful Life, which sees down-and-out businessman George Bailey contemplate suicide on Christmas Eve.

As George is about to leap from a bridge, a guardian angel named Clarence confronts him and shows him what his hometown would look like if it hadn't been for all his good deeds over the years.

Anyone experiencing suicidal thoughts should contact the National Suicide Prevention Lifeline for confidential support on 1-800-273-8255.