The agency said the vehicle was traveling eastbound in the 300 block of Pacific Coast Highway around 12:45 a.m. when it struck a curb and then hit the construction equipment, ultimately leading to the death of three passengers.
Three construction workers suffered minor non-life-threatening injuries and were sent to a local hospital, police said.
PCH was closed in both eastbound and westbound directions from Superior Avenue to Riverside Avenue.
The investigation is ongoing.
Authorities encourage anyone with information regarding this fatal incident to contact Traffic Investigator Austin Lavery at email@example.com.