The sister of an 18-year-old tourist killed when a maniac driver plowed through crowds of pedestrians in Times Square recalled the horrific experience on the stand Monday — telling jurors she was “just trying to lay there [and] not die.”

Ava Elsman, now 18, was the first witness to testify in the Manhattan trial of Richard Rojas, who is accused of killing Alyssa Elsman and injuring 22 other people in the May 18, 2017 rampage.

“I just looked up and I saw the car turn and that was the last thing I saw,” said Ava, who was 13 at the time and on a family trip to the Big Apple from Michigan.

“Everything went black but I heard the engine running,” she testified. “I could hear people screaming and running but it was all black.”

Ava said she “woke up on the sidewalk” with people all around her and “could not physically feel anything because all of the blood I was losing.”

“I was in and out of consciousness,” she told the jury. “Someone told me to put my leg down or I would bleed out.”

Ava said, she was “just trying to lay there [and] not die.”

Assistant District Attorney Alfred Peterson said Rojas, a 31-year-old Navy veteran, was well aware of the carnage he was causing when he drove into crowds at the “Crossroads of the World.”

“For three long city blocks, in the most congested pedestrian thoroughfare, probably in the world, he drove his car at ridiculously fast speeds … and he caused unthinkable destruction,” Peterson said in his opening statement.

Bodies “were all over the hood of his car. They were smashed up against his windshield.”

It was “impossible for [Rojas] not to know exactly what was happening,” Peterson said. “But he didn’t stop.”

After Rojas finally crashed his Honda Accord, his first words to a traffic agent were, “I wanted to kill them all,” the prosecutor alleged.

Ava, who now works as a hostess at a Michigan restaurant, said doctors were forced to intubate her while she was awake, which she described as “the worst physical pain I ever felt.”

When she finally awoke in the hospital bed she asked her mother about Alyssa and “[Her] face dropped.”

“When there were no words, I knew exactly what happened,” she told the jury, referring to the moment she knew her older sister was dead.

“It’s hard because there are a lot of things I’ve done in my life I want [Alyssa] to physically see,” Ava said. “I know in spirit she can see me [but] I physically want to give her a hug.”

“A whole piece that was ripped out of my life,” she continued. “I get jealous watching people with their families because I don’t have that anymore.”

Peterson said during the course of the trial – which is slated to last several months – prosecutors will call many victims of Rojas’ “horrific, depraved act,” including New Jersey teen Jessica Williams who was “basically cut in half by Richard Rojas’ car.”

“Her pelvis separated her from her spine. They had to literally put her back together from two pieces into one,” Peterson said of Williams.

Ava – who broke three ribs, had a collapsed lung, fractured her pelvic bone and had compound fractures in her leg – faced months of rehab after and couldn’t walk again until September of that year, she told the jury.

She was so traumatized that she never got a driver’s license and dropped out of school.

The prosecutor said Rojas “was hopeless and stoned” when he plowed through the vulnerable tourists, leaving their bodies “literally stacked on top of each other,” in his wake.

Rojas admitted to cops after his arrest that he had been smoking marijuana laced with PCP before incident, authorities have said.

His defense attorney Enrico DeMarco, argued the insanity defense, saying Rojas lacked the mental capacity to understand his actions.

“This a case about a 26-year-old who lost his mind,” DeMarco told the jury.

Rojas also faces a slew of lawsuits from victims. The civil cases are on hold pending the outcome of the criminal trial, which had faced various delays over the last five years, including the court shutdown caused by the pandemic.