A victim in the double fatal shooting on a sleepy Long Island block desperately called out for help as he lay dying on a rainy street, a neighbor told The Post on Thursday.

“He was on the driveway crying for help,” the tearful man, who did not want to be named, said Thursday -— adding that the victim was “crying, ‘Help, help.’”

The double homicide occurred on Lakeway Drive around 11:20 p.m. in West Babylon, police said.

When responding officers arrived, they found 21-year-old Olivia Digrigoli of West Islip shot inside a red Jeep and 22-year-old Anthony St. Hilaire of West Babylon gunned down outside the vehicle, cops said.

Digrigoli was pronounced dead at the scene, while Hilaire was pronounced dead at a nearby hospital.

The neighbor said he called 911 after hearing six gunshots. He then ran out to help the mortally wounded man.

“I said, ‘Keep it up, man, don’t talk,’” the man said, noting that while he was waiting for police to come, he “heard a car speed away.”

The neighbor said when police arrived, he overheard the dying man say “my girlfriend” before oxygen was administered to the man.

He added that the woman inside the car “was shot on the left side of her head.”

“The car was on,” the neighbor said.

Typically, the neighbor said, the area is a “peaceful place.”

“There was so much rain last night … I don’t know what was going on because it’s a dead end.”

Another neighbor called the double shooting “shocking.”

“It’s very quiet over here,” she said. “The neighbors are older people that live here. It’s quiet.”