A 21-year-old woman was killed Thursday night in Mission Viejo, California, in a crash investigators say occurred during an alleged street race, and her younger brother is among two people arrested afterward.

What investigators say happened

According to authorities, two vehicles were allegedly racing near Los Alisos Boulevard and Mustang Run around 9:41 p.m. Thursday when one of the cars left the road and struck a tree. Shalia Deciderio, of Rancho Santa Margarita, was pronounced dead at the scene. Loved ones said she was the mother of a young child.

Her younger brother, 20-year-old Aiden Deciderio, was arrested Friday morning. Jaime Rojas, 20, identified as the driver of the second vehicle allegedly involved in the race, was hospitalized in critical but stable condition and is expected to be booked upon release. Both face potential charges of vehicular manslaughter with gross negligence; authorities have not said whether drugs or alcohol are considered factors, and the investigation remains open.

A photo of Shalia Deciderio holding a bouquet of flowers, shown alongside a nighttime photo of police vehicles at the crash scene
Shalia Deciderio, 21, was pronounced dead at the scene of Thursday night''s crash.
FOX 11 Los Angeles coverage of the Mission Viejo crash and arrests.

A family tragedy

Investigators have not detailed the exact relationship between the two vehicles allegedly involved in the race, or Aiden Deciderio's specific role, beyond confirming his arrest on suspicion of vehicular manslaughter with gross negligence. IF Daily has not independently verified all details of the allegations, which remain under investigation by Orange County authorities.