Darrell Hack of Callahan says his last memory of his daughter, Janey Flaherty, was her waving goodbye over his ex-wife’s shoulder as they walked through the airport.

"Last time I seen her she was going down the corridor with her mom, and she was waving bye-bye," Hack said.

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Hack divorced the girl’s mother when she was just over a year old — and when they left, he never saw Janey again. The two, he said, disappeared to Kentucky.

One of the only things he had was an old photo of Janey that he’s held onto for four decades. Her trail grew cold.

"I tried calling, tried getting a hold of her and nothing," Hack said.

But on Saturday, he received the shock of a lifetime the day before Father’s Day. Janey, now a mother of two, found her father on Facebook and located his phone number.

"She called me last night. The best Father's Day I've ever had in my life," Hack said. "I prayed every night that I'd see my baby.”

Janey Flaherty said her dad is what she was missing.

"It means the world to me to be able to finally tell him happy Father's Day,” Flaherty said. "It was a relief … like I had been missing something my whole life.”

As for a reunion, it’s happening soon. Hack says he can’t wait to meet the two granddaughters he didn’t know he had.