Tim Putnam watched as the dog fell into the ice-filled waters of Betsie Bay in Michigan. 20 minutes later he had waded his way through the ice to the dog's rescue.
Tim and the folks at the animal shelter who treated the dog for hypothermia are calling her Betsie. If no one claims her, Tim is going to adopt.
"Maybe it was just meant to be," he said.
Using 3D printed prosthetics, Derby the dog can now walk and run for the first time in his life.
He was born with small forearms and no front paws like a furry little T-Rex, and he could only move around on soft surfaces as a result of the deformity.
So 3D Systems created some new legs for him using a 3D scanner and a multi-material 3D printer that could build both the sturdy base and comfortable rubber cups.
“He runs with Sherri and I every day, at least two to three miles,” said his owner Dom Portanova. “When I saw him sprinting like that on his new legs it was just amazing.”
Watch him in action in the video above.