What started as a volunteer opportunity turned into a remarkable 40 years of friendship for Brad Crossley and Phil O'Hara.

The duo met when Crossley was 11 and O'Hara was 23. They were paired through Big Brothers, Big Sisters.

At the time, Crossley was being raised by his single mother.

“By the time I was 10 years old I had lived on 10 different streets, apartments and went to different schools for numerous reasons. Having a man or a father figure in a boy's life is really important,” Crossley says.

The pair would go to movies and on trips together. O’Hara taught Crossley how to rock climb and drive a car.

“I think anyone who goes into this program, to have a very positive influence on that young person and opening up doors,” says O’Hara.

Over the years they've stood in each other’s weddings and named their own sons after one another. Crossley followed in O’Hara's footsteps by becoming a gym teacher. Recently, Crossley inspired O’Hara to cycle, and he lost 70 pounds as a result.

"Sometimes we say we are big brother, little brother, but mostly we just say we are brothers,” O’Hara says.

And there are 100 other kids in the greater Halifax area waiting for a similar friendship.

“Eighty per cent of them will be boys on our waiting list,” says Carol Goddard, executive director of Big Brothers Big Sisters. “The priorities right now are to interest volunteers in Dartmouth, Spryfield, Fairview, Sackville.”

Last fall, Crossley and O’Hara marked the milestone by recreating one of their original outings.

They've since reflected on what brought them together so many years ago.

“I think that Brad might have just really needed somebody to trust and be there for him unquestionably all the time, and I was ready to be that person,” O’Hara says.

“I encourage anyone that can do it, who has the time and ability to guide a young person and be a big brother or big sister to do it. You won't ever understand how valuable and priceless that is,” says Crossley.

With files from CTV Atlantic’s Kelland Sundahl.