Barnes was standing Saturday in a torrential storm and watching the worst flood in memory in flood-prone Ellicott City, Maryland, in what was quickly becoming one of the worst nights of his life.
He had just fled his store, All Time Toys, his lifelong dream, as it filled with water. He spotted his Mercury Grand Marquis floating with other cars down Main Street.
Just as suddenly, Barnes' thoughts weren't focused on his store, his car and his future.
He saw a woman trapped in a car that had washed down the street and now was stuck and being battered by water cascading over its top and hood.
"I'm not a strong swimmer," 29-year-old Jamie Knight told CNN affiliate WJZ. "So I was really afraid of getting washed down the street."
Barnes plunged into the thigh-high water, trying to battle his way to the car, a bystander capturing the selfless act on video.
"I just emptied my pockets and went out there to see if there was something I could do," he said. "There was someone in danger."
Barnes, a good-sized 36-year-old, didn't get far -- and came close to dying himself. The water knocked his feet out from under him and sent him 20 or 30 feet down the street.
"He was swept away -- he could have died," the man who shot the dramatic video, David Dempster, told WJZ. "This guy is a hero."
Barnes regained his footing. He came back to try again.
This time, Barnes and fellow shopkeepers made a human chain; one man anchoring himself by a storefront and grabbing hands with another, allowing Barnes to get close to Knight.
But not close enough -- there was still several feet of space between Barnes and the car.
Knight, who was leaning out the window, appeared fearful of leaving the vehicle. Rescuers shouted she had to get out; otherwise she would likely drown.
Barnes took another plunge, letting go of his link in the chain, and he nearly got knocked off his feet again. He regained his footing, and made his way to the car and embraced the victim, lifting her out of the car.
His partner, who had retreated momentarily, returned and grabbed Barnes' outstretched hand, allowing Barnes to carry Knight to safety.
It all made a very bad day, a good one. When asked about it by CNN, Barnes deflected the hero label. "I didn't think there was anything special going on," he said. "You do what you need to do to help someone."