WINNETKA (CBSLA.com) — Police are investigating a horrific three-car crash along Roscoe Boulevard in Winnetka that killed a single mother.

The crash, which was reported just after 2 a.m. on Roscoe Boulevard and Irondale Avenue, may have involved alcohol, possibly drugs, according to police. Speed was also a factor in the crash.

Police say a man in his 20s driving a speeding Dodge Challenger plowed into a Subaru, which spun out of control, and then crashed into a Ford driven by a woman in her early 20s heading home from work. The force of the impact threw the Ford into a tree and killed the woman.

Officials say the driver was going two-to-three times the 40 mile-per-hour speed limit.

Chris Golden was on the scene of the crash soon after it happened and was visibly shaken by what he saw hours later.

“I looked over and saw the vehicle that unfortunately had someone that passed,” Golden said, trembling.

A family member told CBS2 News that the mother’s son was just 12-years-old.

A longtime coworker of the mother killed by the suspected DUI driver said her name was Rosario.

“This makes no sense to any of us. We are incredibly saddened and her coworkers are completely devastated,” the coworker said. “This child will be devastated for the rest of his life. He’s out of a mother who was a great citizen and outstanding member of society. It’s just a shame.”

A neighbor, Laura Cora, rushed over to help Rosario but one look at her car, there was nothing Laura could do.

She just found out Rosario was a mom like her.

“I have two daughters. Oh my God,” Cora said.

The coworker said there is no reason anyone should drive impaired, especially when ride sharing is available.

“Her son will never be the same. It’s incredible devastating to the families. There’s no excuse for drinking and driving,” the coworker said.

There were a total of five people in the three cars.

The driver of the Subaru suffered minor injuries, but the three inside the Challenger all had to be extricated, according to LAPD Capt. Andy Neiman.

“At some point, the vehicle caught fire. Citizens who were in the area responded to assist and they were able to control the fire until the fire department got here,” he said.

The driver of the Challenger is hospitalized in critical condition, while the two others that were in the car with him suffered serious injuries.

Police initially suspected the crash may have been related to street racing. Police later said preliminary test results show the driver was under the influence of alcohol, possibly drugs.

The driver of the Dodge is under arrest. Once he is released from the hospital he will be booked.