Four high school students and an intermediate school student were among those involved in a fatal solo-vehicle crash in Santa Ana that killed four over the weekend, authorities said Monday, April 7.

Among those killed were three Santa Ana Valley High School students – including the driver who had recently turned 18 – and a 20-year-old woman, Officer Natalie Garcia said. Their identities had not yet been made public by police.

Another passenger, a girl who attends Carr Intermediate School, was in grave condition at the hospital, Garcia said.

The sixth occupant, a girl who attends Santa Ana Valley High School, was expected to survive.

“Our entire SAUSD community is devastated by this unimaginable loss. We extend our deepest condolences to the families and loved ones of the victims, and our thoughts remain with the two individuals who are recovering,” the Santa Ana Unified School District said in a statement Monday. “We are working closely with local law enforcement as they continue their investigation into the circumstances surrounding the accident. In the meantime, our focus remains on supporting the students, staff, and families affected by this tragedy.”

The district said crisis counselors and mental health professionals will be made available at both Valley High School and Carr Intermediate School to support anyone in need and are in contact with the families of all the students involved to offer support and assistance.

It was unclear where the six occupants were headed in the Lexus sedan before the crash, which occurred shortly after Segerstrom Avenue curves to the right.

The driver was believed to have been speeding before colliding with a tree in the median while traveling westbound between Raitt and Greenville streets just before 11:25 p.m. Saturday night, police have said.

Among the crash victims were two pairs of sisters and another family member related to one of the pairs, Garcia said, though as of Monday it was unclear which of them were among the dead.

The crash occurred near Carl Thornton Park and police have said that some of the occupants were wearing seatbelts while others were not. The driver was believed to have been speeding before the crash, police have said.

Drugs or alcohol may have factored into the crash.

A memorial of white crosses, flowers, balloons and candles was erected in the median on Sunday and continued to grow Monday, with a handful of people stopping by the crash site.

Angel Garcia, 17, stopped by the median Monday afternoon and set down a candle and a bouquet of red silk flowers after learning his ex-girlfriend had been among those killed.

“It’s really hard, I’ve never experienced this pain in my heart,” Garcia said. “Never in a million years did I think this would happen.”

Garcia found out about the crash from a cousin of the girl, whom he said he dated for two years after they met through social media. They attended Carr Intermediate School together, he said, adding that she loved red flowers.

He described her as a sweet person, always kind.