SAN DIEGO (KGTV) -- A San Diego native made history at the Ironman World Championships in Hawaii, becoming the first above-the-knee double amputee to finish what many consider the world's most grueling endurance race.

Roderick Sewell crossed the finish line of the 140-mile triathlon race in 16 hours and 26 minutes and immediately embraced his mother. The two lived in San Diego homeless shelters when Sewell was growing up.

"It's amazing to see how far we've come in 20 years," said the 27-year-old.

It's even more amazing when you consider that Sewell had never completed a marathon before Saturday's competition. The Ironman triathlon consists of a 2.4-mile swim, a 114-mile bike ride, and ends with a 26.2-mile marathon.

On top of that, Sewell had only six months to train after receiving an invitation from the Ironman organization.

"I had no bike. I didn't own one" until a few months before the competition, said Sewell.

Sewell raced with strategy help from his longtime friend and mentor Rudy Garcia-Tolson. Garcia-Tolson became the first above-the-knee double amputee to finish any Ironman 10 years ago.

"Back when I first met Roderick, he was about 8 years old. He was actually petrified of the water," Garcia-Tolson said. "Whatever life is throwing at you, mental or physical challenges, you have to fight and get over those and strive for better."

Sewell, whose legs were amputated at 2 years old because he was born without tibias, credits much of his success to the San Diego-based Challenged Athletes Foundation. He was introduced to the group at 8 years old.

"I didn't do any kind of sports. I wasn't very physically active," he said. "And then I started with them and got started in every sport I could."

CAF gave Sewell his first running blades at a time when he and his mother were living in homeless shelters.

"If I can inspire someone, it's a blessing," he said.

"When people come up to me and tell me their stories, to me their stories seem more mind-blowing than my own," Sewell added.