The brothers were identified by friends and by the Acorn newspaper as 9-year-old Jacob Iskander and 11-year-old Mark.
People dropped off flowers and toys near the crosswalk close to the crash site.
The suspect was identified as 57-year-old Rebecca Grossman, who has familial ties to the founder of the Grossman Burn Center. Grossman is the co-founder of the Grossman Burn Foundation.
Grossman was arrested on two counts of vehicular manslaughter. She is out of jail on a $2 million bond, according to jail records.
Authorities said the brothers were hit by a car in front of their parents and siblings as they crossed the street Tuesday night at Triunfo Canyon Road and Saddle Mountain Drive in Westlake Village.
RELATED: 2 brothers killed in apparent street racing crash; suspect ID'ed as member of prominent Grossman family
"The children were walking with their family. It is a very tragic situation. The mother and father were able to pull the other two children back in time, and the vehicle struck the two other children," said Capt. Salvador Becerra of the Los Angeles County Sheriff's Department.
One boy died at the scene, and the other died at the hospital. Investigators had cordoned off a crosswalk with crime scene tape, and a scooter and a set of roller blades were seen nearby the crash location after the collision.
"This is a devastating loss for our community," State Sen. Henry Stern posted on Facebook. "Two young boys with an entire lifetime ahead of them. Pray for the Iskander family tonight and hold your loved ones close."
In a statement, the Grossman Burn Center says "Like our entire community, the Grossman Burn Center family at West Hills Hospital is terribly saddened by this tragedy. Our sympathies are with all who have been affected."
Investigators say alcohol and street racing may have played a part in the collision.
According to the sheriff's department, after the collision, it appears one of the boys was carried for more than a hundred feet down the road on the hood of the car. When Grossman eventually hit the brakes, they believe the boy rolled off into the street, and then Grossman ran over him, leaving the scene. She finally pulled over a mile and a half away.
Investigators tell Eyewitness News they have surveillance video of the incident.