NEW YORK (CBSNewYork) — Three veterans, three dogs, and a 100 mile journey to ground zero.

Marines from the New York area embarked on a mission to honor two of their fallen brothers.

READ MORE: 'The Loss Of A Hero': New York Mourns Death Of 22-Year-Old NYPD Officer Jason Rivera

As CBS2’s Erica Von Tiehl reported, they’re also raising awareness about Post Traumatic Stress Disorder.

“He saved my life, that’s the best way to put it. I don’t know where I would be without him,” Sgt Andrew Einstein said.

Many of us have best friends, but few can say they’ve had as big of an impact as Einstein’s service dog Gunner. The Purple Heart recipient returned home with PTSD after serving in the Marine Corps.

“When I got back, things were rough, and him coming into my life, they changed drastically. He’s allowed me to do things that I thought I’d never be able to do again,” Einstein said.

Einstein is now a police officer in West Hampton Township, NJ and is working to raise awareness for PTSD. He’s also honoring two Marines who were killed in action.

Einstein has teamed up with sergeants Devon Richio and Steven Ward, along with their service dogs Kyra and Ava.

READ MORE: Dozens Gather In Harlem To Pray For Families Of NYPD Officers Shot While Responding To Domestic Dispute

They Marines and their dogs are setting off on a hike from the Liberty Bell to 1 World Trade Center.

“If we can help one vet or one family that’s all we can hope for,” Einstein said.

The Marines plan to walk 12 miles a day and arrive in lower Manhattan in time to take part in 9/11 remembrance ceremonies.

“September 11th is kind of the reason why everyone, the reason why we’re here, where we’re at today,” Richio said.

They Marines and their dogs will be staying at a different firehouse each night where they hope to share stories about why they’re walking with firefighters.


MORE NEWS: Lashawn McNeil, Suspect In Deadly Harlem Police Shooting, Was On Probation, Had 5 Prior Arrests