A 9/11 first responder is back on Long Island after completing an 1,850-mile hike along the Appalachian Trail to raise money for Paws of War.

Rob Weisberg, of Nesconset, received a service dog from the nonprofit when his experience at Ground Zero left him with post-traumatic stress disorder.

Weisberg says he had an accounting job across the street from the World Trade Center, and was underneath the towers when the first plane hit.

He says he jumped into action to save as many lives as he could.

“There were so many different times that day that I almost got killed,” Weisberg says. “Suffocating – everybody sees the videos of the gray cloud. They estimated where I was, the wind was 180 mph, OK, I got blown off my feet.”

The longtime Commack Fire Department volunteer survived the day, but spent the next two decades battling survivor’s guilty and suicidal thoughts.

Weisberg found healing on his fundraising trek along the Appalachian Trail.

Every step he took on the 5-month journey across 12 states raised money for Paws of War and heightened awareness for those struggling with PTSD.

Weisberg raised $15,000 for the nonprofit to train service dogs for veterans. His mission is to give those veterans a message of hope.

“If you’re having a tough time, get help,” Weisberg says. “There’s no shame in it, the stigma shouldn’t be there, you know, you’re more important than the stigma. Get help. There’s hope and that’s why you’ve got to keep pushing through.”