According to Los Angeles Police Department investigators, the black BMW sedan may have been traveling more than 100 mph - about triple the speed limit -- when it crashed into a tree shortly before 11 p.m. in the 9900 block of Balboa Boulevard, near Lassen Street.
The car splintered into pieces and erupted in flames after the collision, and its four occupants - two men and two women in their early 20s - were found dead inside the BMW, police said.
The deceased were identified by the Los Angeles County coroner's office as Martin Gomez, 20, of Granada Hills; Denney Lomeli, 20, of North Hills; Amanda Alfar, 22, of Panorama City; and Leena Ammari, 21, of Reseda.
"It was on fire for a good while," said a witness who gave his name only as Mersay. "There a crowd coming around to try to help the people inside, but there was an In-N-Out worker that came by and was alerting everyone that there was gasoline everywhere ... so that we should probably stay back."
As an investigation continued early Saturday morning, skid marks were visible on the roadway at the scene.
Witnesses said the driver may have been racing against another vehicle. Surveillance video, recorded moments before the crash, shows another black sedan speeding.
Los Angeles police were in search of the driver in the dark sedan, which was last seen traveling at a high rate of speed on Lassen Street.
Anyone with information about the incident is asked to call LAPD Valley Traffic Division detectives at (818) 644-8029. Anyone wishing to remain anonymous should call Crime Stoppers at 800-222-TIPS (800-222-8477).