LOS ANGELES—An investigation was continuing June 16 into a fiery, single-vehicle crash that killed four people on the southbound Harbor (110) Freeway in South Los Angeles.

The crash occurred around 11:45 p.m. Thursday near the Slauson Avenue on-ramp, where fire crews found the overturned vehicle on fire with the four people inside the smoldering wreckage, said Brian Humphrey of the Los Angeles Fire Department.

California Highway Patrol (CHP) officials said the vehicle smashed into a freeway barrier off the shoulder of the freeway and burst into flames. Investigators told reporters at the scene that speed appeared to have played a factor in the crash, suggesting the driver may have been racing.

The CHP is investigating the crash.