All lanes were reopened as of 8:40 a.m., the California Highway Patrol said.
Officers responded to the collision at about 5:12 a.m. near Laurel Canyon Boulevard, according to the highway patrol, which issued a SigAlert.
The agency received reports of a disabled BMW on the freeway with one person inside. It was unclear if the BMW's lights were on when it was hit by another vehicle, whose driver was fatally injured.
Whether the driver of the second vehicle applied brakes before the impact was unknown.
The Los Angeles Fire Department initially said one patient suffered traumatic injuries and the other sustained minor injuries. A subsequent update from the CHP said the incident was fatal.
It was unclear if the deceased person died at the scene or a hospital.
All westbound lanes were shut down in the immediate aftermath of the collision, causing a traffic backup that stretched for miles. Shortly after 6 a.m., the Highway Patrol announced the No. 5 lane was open, as were all eastbound lanes.
About 2 1/2 hours later, all lanes were open to traffic.
SIGALERT CANCELLATION IN NORTH HOLLYWOOD: WB US-101 AT LAUREL CANYON BLVD, ALL LANES NOW OPEN— CHP PIO - LA County (@CHPsouthern) December 12, 2016
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