The group held a race Sunday where the deadly crash happened.
The racers met around 7:00 A.M. near Reseda Boulevard in Tarzana.
Shortly after the race began, Garcia racer lost control of his soapbox and crashed into a parked car, witnesses said.
Police say Garcia suffered serious injuries and was transported to a hospital where he died. Garcia was wearing a helmet, but it's unclear if it was properly secured as it flew off upon impact, police said.
The group calls themselves the Illegal Soapbox Federation because its races technically pose a "public safety risk." The soapbox racers can reach speeds of up to 60 miles per hour and can become difficult to control, despite the cars' brakes.