Chain-reaction crash involving at least 7 vehicles on SB 405 Freeway in Long Beach snarls traffic

LONG BEACH, Calif. (KABC) -- A chain-reaction crash involving at least seven vehicles Thursday morning on the 405 Freeway in Long Beach prompted the closure of several lanes.

The crash occurred in the No. 1 lane on the southbound side of the freeway, near Atlantic Avenue. The number and severity of injuries was not immediately known.

Firefighter-paramedics responded to the scene, and one car apparently struck a semitruck as drivers tried to make their way past the wreckage.

The big rig was cleared from the middle lane as the pileup of other vehicles remained along the center median. Southbound traffic, however, remained backed up for miles amid the morning commute.

The cause of the crash was unknown.