The driver who left a woman trapped inside a burning, crashed car on the Gowanus Expressway wasn’t heartless — he was a hero, the man’s brother told The Post.

“He did not just run away from the scene. He lost his phone in the car [and was] unable to call the ambulance,” Waheed Ahmad, 21, said about his brother Saeed Ahmad, 23.

Ahmad crashed a 2007 Infiniti G35 sedan into a concrete barrier Friday morning and hailed a cab while his friend Harleen Grewal, 25, sat burning inside the passenger’s seat, police said.

“He tried to get her out. That’s how his hands and his legs and his neck got burned. He couldn’t get her out. The fire got too crazy. It just burned so quick,” said Ahmad’s distraught brother.

Saeed Ahmad “was in pain” and since “the ambulance wasn’t coming” he asked the taxi to take him to Maimonides Hospital in Borough Park, his brother said.

Police tracked Ahmad down to the hospital where he was charged with criminally negligent homicide, leaving the scene of an accident, aggravated unlicensed operation of a vehicle and speeding.

His family was told by cops that they couldn’t visit or speak to Ahmad until after his arraignment, the family told The Post at their Brooklyn home.

The hospital contacted Ahmad’s friend listed as his emergency contact who spoke to him before police arrived, the family said.

“Everything is chaos right now. We are shocked. It’s horrifying for the girl and her family,” said Waheed.

He added, “He’s emotionally distraught. Every time they ask him about what happened, he’s crying and screaming. His friend burned alive.”

Ahmad is being treated for burns to his extremities at the Staten Island University Hospital.