Just after 1:30 a.m., the California Highway Patrol responded to a jackknifed big rig at the westbound 60 Freeway connector road to the northbound 605 Freeway in the city of Industry.
It was not immediately clear if anyone was injured in the incident, which prompted the closure of the transition road for about two hours.
In City Terrace, a car was engulfed in flames after a 4 a.m. crash involving two other vehicles at the interchange of the westbound 10 Freeway to the southbound 710 Freeway.
Three people were transported to a hospital in unknown condition.
The cause of the collision, which snarled traffic for miles on the westbound 10, was under investigation.