The California Highway Patrol responded to reports of the crash near the Fair Oaks Avenue exit around 4:16 a.m., according to CHP incident logs.
Initial reports indicated what was described as a Toyota 4Runner rear-ended the truck at speed.
Witnesses reported that the SUV became lodged underneath the larger vehicle, with both vehicles becoming fully engulfed in flames shortly after the crash.
Pasadena Fire Department crews were dispatched to the scene, arriving by 4:30 a.m. The incident prompted authorities to stop all westbound traffic as emergency personnel responded.
“Both vehicles fully engulfed,” a CHP officer reported from the scene.
California Department of Transportation crews implemented a full closure of the westbound 210 Freeway at Lake Avenue. The closure included two lanes of the transition road from westbound 210 to westbound 210 and the number five lane on the main freeway.
Pasadena Police Department requested a traffic break at Lake Avenue to manage vehicles already on the freeway. CHP issued a SigAlert for the area with no estimated time for reopening.
According to preliminary reports, witnesses described the car as driving erratically prior to the collision, with one report alleging the “tan hatchback was 23103 prior to TC,” referring to the California Vehicle Code for reckless driving.
Authorities have not identified the dead man.