Motorcyclist killed in crash on 101 Freeway in Woodland Hills

A motorcyclist was killed in a crash on the 101 Freeway in Woodland Hills on Tuesday. 

Circumstances surrounding the incident remain unclear, but all southbound lanes near the Topanga Canyon Boulevard ramps were blocked, according to California Highway Patrol officers. 

They say that the rider was down in the No. 2 lane, which led them to issue a SigAlert for the area. 

The rider, who has not yet been identified, was pronounced dead at the scene. 

It's unclear exactly how long the closure is expected to last. 

SkyCal flew over the site of the crash, where a long line of traffic could be seen extending back for miles. 

This is a developing story. Check back for details.