PSA: Always wear your seatbelt. Yesterday we reported that a 17-year-old with a learners permit crashed his car and was the only survivor out of the whole care full. Now we’re learning that his friends weren’t wearing their seatbelts. Such a shame. Click below for more details.

Melissa

They told their parents they were going to see “Taken 2” and wound up in a horror show that left four of the Queens teens dead.

What happened in the eight hours between the time they supposedly left to catch the Liam Neeson thriller — and when they skidded off a Long Island highway and crashed into a tree early on Columbus Day — was the subject of a criminal investigation Tuesday.

There was only one survivor — 17-year-old Joseph Beer of Richmond Hill, who suffered a head injury and has told police very little about what happened, sources said.

Meanwhile, the families of the victims — all of them 18 years old — were planning funerals and struggling to grasp what happened.

Victim Peter Kanhai’s mom said he left for the movie at 7 p.m. Sunday and she called his cell phone at 3 a.m. Monday when she realized he wasn’t home.

“He said he was at his friend’s house,” Kumaree Kanhai, 39, said. “He said, ‘I’ll be home soon’.”

The devastated mom said she had no idea Peter was on Long Island. She figured he would catch a movie in Manhattan or near their home in South Ozone Park.

But Kanhai never made it home. At 3:40 a.m., police said Beer lost control of his brand new Subaru Imprezza on a treacherous stretch of the Southern State Parkway known to locals as Dead Man’s Curve.

Kumaree Kanhai found out her son was dead when two of his pals knocked on her door. She said she aches for herself, for the other victims’ families, and for Beer.

“They were friends and I don’t really hold any hatred toward him,” Kanhai’s stepdad, Bryant Barr, said. “I’m sure he didn’t wake up and say I want to hurt somebody.”

Police, however, said Beer shouldn’t have been behind the wheel. He only has a learner’s permit. And under the law, a licensed driver at least 21 years old should have been in the car with Beer.

Beer underwent the usual post-crash blood tests and the wreckage was being scrutinized, but it could be weeks before investigators determine whether he was under the influence or driving too fast, officials said.

At that point, Beer could be charged with a crime, Trooper Frank Bandiero of the State Police said.

Heather Senti, chief of the Lakeview, L.I., fire department and one of the first to reach the crash site, said they found “nothing of a suspicious nature.”

“What we found was a tragedy,” she said.

Asked about an unconfirmed news report that Beer and his buddies might have been high and that the wreckage reeked of pot, Senti said “we did not notice that.”

“The only smell we noticed was fuel from the vehicle,” she said. “The only debris we saw was sneakers, backpacks, and what looked like homework.”

Kanhai and the other victims — Chris Kahn, Darian Ramnarine and Neil Rajaba — did not appear to be wearing seatbelts when the car hit the tree and split in two, said Bandiero.

“They were ejected, so no, it doesn’t appear that they did (wear belts),” the trooper said.

Beer, though, appeared to be wearing his. He was found wandering amid the wreckage by the light of his cell phone by first responders, sources said. He was expected to be released soon from Winthrop-University Hospital in Mineola, L.I.

Meanwhile, Richmond Hill High School, the alma mater of Beer and three of the victims, was shrouded in mourning, and grief counselors consoled students in the library.

“It’s tragic to lose somebody so cool,” senior Kayla Valentine, 17, of Springfield Gardens, said of Kahn.

Senior Paramvir Singh said the teens’ deaths was an unwanted lesson in mortality.

“You don’t know what’s going to happen at any time,” said Singh, 18, of Richmond Hill. “You’re here one minute and you don’t know if you’re going to be alive the next minute. It’s really scary.”

Some students also knew Rajaba, who attended Abraham Lincoln High School.

“He didn’t deserve that,” said junior Bianca Bisnauth, 15, of Richmond Hill.