A pregnant woman and her fetus were among the five victims pronounced dead at the scene, which also included three other adults, according to the California Highway Patrol.
A law enforcement source familiar with the investigation told NBC News that a 3-year-old child was also killed in the crash.
The California Highway Patrol later confirmed that another victim's remains were located in a search of the wreckage at the crash site, bringing the number of deaths to six including the fetus.
One adult and six minors -- the youngest being 13 months old and others ages 8, 11, 13, 14 and 15 -- were hospitalized for minor injuries in relation to the accident, CHP and the Los Angeles County Fire Department confirmed via NBC Los Angeles.
An additional victim declined to be transported to the hospital.
The crash took place at a Windsor Hills intersection and was reported to local authorities at around 1:40 p.m. local time.
Additional information about the victims, such as whether they were all traveling in vehicles or pedestrians, was not immediately made available on Thursday.
Three of the six victims involved in the crash were in flames when California Highway Patrol officers arrived at the scene, according to Pepi.
Authorities said the exact number of vehicles involved in the initial crash hadn't yet been determined.
California Highway Patrol is continuing to investigate the crash and believes speed played a contributing factor.
Pepi specified that a vehicle, later identified as a Mercedes-Benz, was speeding southbound on La Brea Avenue and is believed to have run through a red light before being struck by another vehicle.
At least two vehicles were shown mangled and burned on a curb after the crash in footage shared by FOX 11 Los Angeles.
KTLA identified the Mercedes-Benz driver as a female who is hospitalized "with major injuries."