Saturday’s fatal crash in Thornton was the result of a high speed rear-end collision that engulfed a car in flames, killing two parents and their two daughters, according to a news release from police on Tuesday.

In the aftermath, two brothers and sons of the victims spoke out on the loss of their family in the crash.

Thornton Police Department officials said a Subaru, moving “at a high rate of speed,” rear-ended a Ford SUV at a stop light, rupturing its gas tank and causing the SUV to catch fire. A Chrysler van was also involved in the crash after the initial impact, according to police.

The SUV was stopped at Washington Street and Thornton Parkway.

Four people died in the SUV, while the driver of the Subaru sustained serious injuries. There were no injuries suffered by the occupants of the Chrysler van, according to police. The Adams County Coroner’s Office have yet to release victim identification.

Meanwhile, two brothers of the family told Denver Gazette news partner, 9NEWS, it was their two sisters and parents who died in the crash.

9NEWS spoke to 20-year-old Adam Diaz and 22-year-old Daniel Diaz. They said police told them their family was rear-ended, pushed into the intersection of Thornton Parkway and Washington Street, where they were T-boned by another vehicle.

The brothers said their sisters Paola, 15, Nataly, 10, and their parents Beatriz, 49, and Fransisco, 49, died in the crash.

Authorities are withholding confirmation of identities until the coroner’s office makes its report, police said in a statement.

“It just didn’t feel real. I was really just hoping it was a nightmare and not something that actually happened,” 20-year-old Adam Diaz told 9NEWS. “I got there pretty quick, but everything was already on flames. So, there was nothing anybody could do.”

Asked what the brothers need most, Adam’s older brother, Daniel Diaz said: “Guidance.”

“It’s really hard for me. I’m 22, but I’m still growing. I’m still learning. I’m still trying to make decisions on my own. It’s hard,” he said.

The Diaz brothers said they both had business dreams that involved their father.

“She told us to keep going. It’s kind of what they would want, not to give up, no matter what,” Adam said.

Adam and Daniel dreamed of buying their parents a house. Now they will have to make home for themselves.

“I’m really grateful I still have him,” Daniel said, “I could not have done this by myself.”

A GoFundMe page, one that appears to be created by a family member of the four victims, was posted on Sunday. The fundraiser, which aims to raise $30,000, has raised over $65,000 in two days.

Police said the Subaru driver, identified as male, is currently recovering in the hospital.

At the end of the investigation, authorities do “fully intend on moving forward with charges if appropriate,” a Thornton police spokesperson said.

Authorities are currently reviewing evidence and reconstructing the crash scene, police said

In a statement, a Thornton police spokesperson told The Denver Gazette: “We are deeply saddened by this tragic event. “We can only imagine what the surviving members of the family could be feeling and going through here just days after their tremendous loss.”

Anyone who has information about the crash is asked to call Thornton Police at 720-977-5150.