The investigation of a fatal four-vehicle crash stopped traffic in both directions on the 405 Freeway in the Sepulveda Pass for several hours overnight.
Three cars and a motorcycle were involved in the chain-reaction collision at Mulholland Drive on Tuesday night that sent debris flying.
At 8:52 p.m. Tuesday, the California Highway Patrol was alerted to the crash, which blocked lanes on the southbound side of the freeway, CHP spokesman Officer Patrick Kimball said.
It started when the driver of a Toyota Tundra on the northbound 405 lost control and struck another car, officials said.
Debris from the crash flew onto the southbound freeway and struck an Audi. The driver of a Volkswagen swerved to avoid the debris but instead struck a motorcyclist.
Paul Goldhammer, 39, of Van Nuys, was pronounced dead at the scene after being thrown from his motorcycle.
Two people were taken to a hospital in fair condition, said Los Angeles Fire Department spokeswoman Katherine Main.
Traffic in both directions was shut down to allow officials time to investigate and to remove debris, Kimball said. A SigAlert was issued shortly after 9 p.m.
Southbound lanes were reopened at about 12:30 a.m. Wednesday, said CHP spokesman Officer Francisco Villalobos. Northbound lanes reopened at about 1:45.