Police activity shut down the northbound 101 Freeway in Hollywood Thursday morning ahead of the commute.
All lanes were blocked on the northbound side at Western Avenue, the California Highway Patrol said.
The closure came at 4 a.m. as many commuters were getting ready to hit the road.
The Los Angeles Fire Department and Los Angeles Police Department were assisting.
By 6 a.m., all lanes had reopened and the SigAlert was canceled.