The six teenage girls who died in a crash with a semi-truck in Oklahoma were packed into a car with just four seats, authorities said Wednesday.

A 16-year-old girl was driving a four-passenger 2015 Chevrolet Spark hatchback with five other teens inside when the subcompact car collided Tuesday with a semi-truck in Tishomingo, killing all six occupants ranging in age from 15 to 17.

Only the teen driver from Connerville and her 17-year-old front-seat passenger were wearing seatbelts at the time, according to an Oklahoma Highway Patrol crash report obtained by The Post.

All of the victims, five of whom lived in Tishomingo, were pronounced dead at the scene, where the small car was obliterated.

The driver of the Peterbilt semi-truck, Valendon Burton, 51, of Burneyville, was wearing a seatbelt and was not hurt.

The cause of the deadly wreck remained under investigation Wednesday, authorities said.

No criminal charges have been filed in the crash, OHP spokeswoman Sarah Stewart said.

The six girls had attended Tishomingo High School, where they were known by many of its roughly 240 students, Superintendent Bobby Waitman told The Post.

Classes at the school, where Waitman visited earlier in the day, were in session Wednesday, he said.

“We are open because we feel like the school is a place where many of our students want to be and we feel like they need something constant in their lives,” Waitman told The Post. “Many of them need to be with each other today.”

The mood among the students at the school was “somber,” Waitman said.

“They feel the loss. But at the same time, as they saw staffers ready to greet them and that they’re grieving with them, we just hope and pray that there’s some relief for the kids,” he said.

Waitman said he had “limited interactions” Tuesday with some relatives of the young victims, who were in grades nine through 12 at the high school. He declined to elaborate on their identities aside to say they were well-known and involved in extracurricular activities.

“They were known, they were not just a number,” Waitman said. “They were not just another student. These young people were loved by this community, and their loss is a great one to everyone involved.”