The tragedy that unfolded off a Florida highway Thursday night started with an act of compassion, when Dhimitri Andoni stopped his car on the shoulder of Interstate 275 in St. Petersburg. The 22-year-old had seen a vehicle swerve and become stranded on the median, and he wanted to help.

Soon afterward, the stranded vehicle returned to the highway, and Andoni walked back to his own car, a four-door 2015 Hyundai, according to Florida Highway Patrol spokesman Steve Gaskins.

It was then, authorities said, that a 1996 Ford F-150 truck came hurtling down the highway and struck Andoni — apparently killing him.

Video footage showed the driver of the truck getting out of his truck and checking to see whether the man he had struck was dead, Gaskins said.

The man then took Andoni’s Hyundai and drove off, leaving his truck behind along the median, Gaskins said.

Authorities identified the man as Dana Thomas Byrd, 30, of St. Petersburg.

“Byrd stopped after the impact happened,” Gaskins told The Washington Post. “He figures out that [Andoni is] dead, gets into his car and drives off. It couldn’t be any more of a weird situation than that.”

It’s unclear why no one stopped to help Andoni after he was hit at about 9 p.m. Thursday, or whether any passersby witnessed what happened. Hours later, Andoni’s father used GPS to track down the Hyundai — which had been abandoned at an office building about two miles north of the crash site — and reported his son missing, authorities said.

Byrd apparently left his wallet inside the Hyundai, Gaskins said. In addition, the entire incident was captured on a GoPro camera that had been functioning as a dash cam inside Andoni’s car, he said.

“We have a GoPro video of basically the victim pulling over to help, getting struck, the guy stealing his car, dropping it off, the whole nine yards,” he said.

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According to Gaskins, a road ranger with the Florida Department of Transportation tagged the abandoned pickup at about 3:40 a.m. Friday.

It wasn’t until 12:30 p.m. Friday, however, that another road ranger discovered Andoni’s body in the median near the abandoned truck, Gaskins said.

Andoni had been enrolled at the University of South Florida St. Petersburg since the spring of this year, and was studying finance, according to the university.

A spokesman for the Clearwater Marine Aquarium confirmed Andoni had worked at the retail store there. “A very sad situation,” aquarium spokesman David Yates said in an email to The Post. “He was considered a thoughtful and upbeat person, well liked by our team members.”

On Friday night, troopers arrested Byrd at his home in St. Petersburg, about three miles west of where the Hyundai had been abandoned. Byrd has been charged with grand theft auto and leaving the scene of a crash involving a death. He is being held at the Pinellas County Jail with bond set at $100,000.

Records from the Pinellas County Sheriff’s Office show Byrd has been arrested in that county 16 other times since 2005, for offenses including “criminal mischief to a place of worship,” retail theft, trespassing, neglect of a child and driving under the influence.

Authorities are looking to question the driver Andoni originally stopped to help. They are also asking anyone with information about the incident to contact Crime Stoppers at 813-558-1800.

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