BLOOMINGTON (CBSLA) — A family is in mourning as they, along with authorities, try to figure out what could have led to the accident that killed three young siblings in the Inland Empire Sunday night . Andrea Jauregui, 13, and her brothers Jose Manuel, 17, and Angel, 20, were killed in the community of Bloomington when a red Dodge Challenger lost control and struck them, police said. They were walking on the 18200 block of Slover Avenue around 9 p.m. with their mother Maria Luna Jauregui, who suffered moderate injuries. The impact of the crash was so loud, neighbor Paulina Hernandez heard it blocks away. “I heard the sounds last night. My husband said, ‘Hey, there’s a big bang. Let’s go and see what it is.’ I said, ‘Probably a semi-truck hitting the speed bump.’” A neighbor of the family became emotional as she spoke about the youths. “That is so sad. I’ve known them for a long time,” Maria Aviles told CBS2 News. “They used to live here with us, but, I mean, I am so sad.[…] It’s so terrible.” “Smoke, so I went over there just to see if nobody was hurt,” said neighbor Lorenzo Cardenas. “Like, three kids — I can’t believe it.” “This is hard to believe when it hits home, you know. You see them — the kids just yesterday, you know, and just for a simple walk,” Hernandez said as she choked back tears. She lost her 21-year-old son in a car accident years ago, so she knows the pain the family is feeling. The California Highway Patrol said the driver of the Challenger was 19-year-old Leonardo Bravo of Bloomington. They believe he lost control and slid across four lanes, striking the family. Bravo remained at the scene of the crash and waited for police to arrive. Witnesses said they saw a dark-colored SUV leaving the scene, and police are now trying to find out if the crash was a result of street racing. Neither alcohol nor drugs played a factor in the accident, and Bravo has not been charged with a crime, said police. The posted speed limit on Stover is 50 mph, but neighbors said people speed down the street frequently. They said they have asked the county to install another stop sign in the area. Hernandez said she’s been trying to make the street safer. “I had to fight and sign a petition to get a stop sign right here, right on the corner of my house because there was just too many accidents, and they made us believe that this is gonna be better, it’s gonna be safer, and it’s been worse,” said Hernandez. “Look, three lives! How many lives is it gonna take for the county to hear? Put cameras, put, I don’t know, more stop lights or something, because we are the ones who are losing our loved ones.” A GoFundMe campaign has been started for the family to help with the siblings’ funeral costs. The family said Angel was getting ready to attend his junior year at Cal Poly Pomona to study computer engineering, with his brother Jose Manuel hopefully following in his footsteps. Andrea was getting ready to start high school.