As per the report, a vehicle was driving wrong way prior to the collision.

Oceanside, CA. – One person was killed in an early Thursday morning traffic collision on Interstate 5 in Oceanside.
According to the California Highway Patrol, the incident was reported at around 2:43 a.m. on the southbound 5 Freeway, north of Las Pulgas.
As per the report, a vehicle was driving the wrong way prior to the collision.
One person, whose identity was not disclosed, died at the scene.
No additional information about the mishap was available.
An investigation is underway.