Twin 1-year-old babies were found dead and foaming at the mouths in the back of a car in The Bronx on Friday — after being left in the hot vehicle for eight hours by their father, who told cops he had forgotten they were there, law-enforcement sources told The Post.

The father, Juan Rodriguez, 39, of Rockland County, was charged early Saturday with two counts of manslaughter and two counts of criminally negligent homicide.

It was 8 a.m. when Rodriguez left daughter Mariza and son Phoenix in the back seat of his Honda Accord, which he parked at the James J. ­Peters VA Hospital in Kingsbridge where he works as a social worker, police said.

He returned to the car at 4 p.m. — and realized the babies were inside only after he had begun driving away, police said.

Someone other than the father called the police after witnessing the man screaming on the side of the road at Kingsbridge Terrace and Kingsbridge Road, police said.

EMS arrived to find the babies not breathing, their mouths covered in foam, sources told The Post.

The children’s mother was talking to police Friday night at the 52nd Precinct station house, where her husband was being held.

The deaths shocked the children’s neighbors in the Rockland County hamlet of New City.

The family had just celebrated the twins’ first birthday with a large backyard party, said one next-door neighbor who asked not to be identified by name.

“I’ve never seen them outside unattended,” the neighbor said of the twins and their older brother, who is 4. He described the parents as loving and attentive.

“Very good parents,” he said.

“They were July babies. It was just this month they had a big party — a bouncy house, the whole thing.”

Another neighbor expressed his sympathy for the father, asking, “How do you live your life after something like this?”

“He would never hurt his children,” the neighbor added. “He’s a very loving father … it’s beyond crazy. That’s a parent’s worst nightmare, it really is.”

The father had dropped off the couple’s older child in Yonkers earlier on Friday, according to a law-enforcement source, who said that child is OK.

The father has two older children from a previous marriage who also live at the home, another neighbor said.

“It’s shocking,” said a Bronx man who gave his name as Leonard P., 27, near the 52nd Precinct station house. “I know there are two little angels in heaven tonight. I hope they get a beautiful burial.

“But the dad? Lock his ass up.”

Other devastated neighbors built a makeshift memorial of votive candles across the street from where the father pulled over the car and fell apart.

The outdoor temperature had risen into the high 80s on Friday.

But even an outdoor temperature of only 61 degrees can cause fatal conditions inside a closed car, where the temperature can reach more than 105 in just an hour, according to Consumer Reports.

An average of 38 children die annually in the US after being left in cars.

Last year, a record-high 52 children died in hot cars, according to the National Safety ­Council.

Additional reporting by Laura Italiano