A 9/11 first responder from Holtsville was matched up with a service dog that turned out to be much more than just man's best friend.

FDNY firefighter Tom Prin Jr. was one of countless first responders who rushed to ground zero hoping to find survivors.

After 9/11, Prin Jr. continued to work as a FDNY firefighter, but in 2006, he fell on a fire escape while fighting a fire in Brooklyn and fractured his spine.

After enduring six spine surgeries, he heard about Canine Companions, a nonprofit that matches people living with disabilities with service dogs - free of charge.

At first, he didn't think he'd be a good candidate, until he met his perfect match -- a yellow lab named Halona.

"She's done more for us than anyone will ever know," he says.