An out-of-control driver killed two children and injured their mothers Monday while they were crossing the street at a busy Brooklyn intersection.

The New York Post reported that the scene was chaotic. The mother of the 1-year-old worked frantically to revive her son after the stroller was dragged about 100 feet. A 4-year-old child was fatally struck and her pregnant mother suffered serious injuries.

“The mom was sitting there next to him screaming,” Andrew Macaluso, a fourth-year medical student, told The Post while describing Lauren Lew, the mother of the 1-year-old. “She was just kind of, ‘Oh, God, this can’t be happening. Tell me this isn’t happening. What’s going on?’ ” Macaluso said of Lew.

“I said, ‘Are you the mom,’ and she said, ‘Yeah.’ … The child had blood on his face. She wipes off his face and gives him air while I’m giving him chest compressions.”

A female driver in a white 2012 Volvo rammed into them in a crosswalk at around 12:40 p.m., the New York Post reported.

“The kids were run straight over, and the driver tried to get away and hit a car,’’ a witness who declined to give his name told the paper. “I don’t even want to think about this. … Just to know those kids were ran down like a dog.”

The paper quoted law enforcement sources as saying the driver struck up to six cars after mowing down the young family. The sedan then came to a rest on the side of the street — with a crushed stroller under its back wheels.

The driver, a 44-year-old woman, was taken into custody, police said. “It doesn’t look like anything deliberate at this point, but we have to figure it out,” NYPD Chief Spokesman Stephen P. Davis told The New York Times. “It is terrible.”

The driver claimed she had “a medical impairment,” the paper reported.

James Long, a Fire Department spokesman, told The New York Times both children were declared dead at the scene.

“She hit the mother, she hit the little girl and she took the carriage — the baby that was in the carriage,” Jessica Sierra, 43, told The Times.

Sierra said she tried to help the girl with a sweat suit from her pack.

“There was blood everywhere,” Sierra said. “And I felt like she was cold, so I covered her with it. She looked lifeless.”