AZUSA ( — A 4-year-old girl was killed and six other people were injured Monday in a car crash in Azusa.

Two vehicles, a truck and a transit bus, were involved in the accident, which took place at 8:40 p.m. at Citrus Avenue and Gladstone Street, police said.

READ MORE: Actor Ricky Schroder Argues With Costco Employee About Mask Confusion

Daniel Romero, who lives down the street from the scene of the accident, said that he heard a loud crash. He ran to aid the victims, and was one of the first to give CPR to the young girl.

“I have a two-year old at home,” Romero said. “So I went home and just started bawling, and it still hits me, and I try not to cry but it still happens.”

The girl, who was riding in one of the vehicles, was airlifted to a local hospital, where she later died.

READ MORE: Pursuit And Standoff Ends In Riverside With One Suspect Under Arrest

Two adults and two children were also injured and transported to a hospital. Their conditions were not immediately known.

Two bus passengers sustained minor injuries, but only one of them was transported for treatment.

Police say that they did find car seats in one of the cars, but they are still investigating whether or not they were properly secured at the time of the accident.

MORE NEWS: Mandatory Evacuations And Warnings Remain For Palisades Fire; Investigators Continue Search For Suspected Arsonist

The cause of the crash was under investigation, however, police say street racing was not a factor.