A jackknifed big rig prompted a SigAlert on the 60 Freeway in Boyle Heights late Thursday morning.

The crash was reported around 11:45 a.m. along the westbound side of the highway near the Indiana Street exit, according to the California Highway Patrol.

The big rig was carrying at least three vehicles when it went on its side. Aerial video from Sky5 showed the truck blocking several lanes of the highway and traffic in the area backed up for miles.

The SigAlert was issued around noon, the CHP reported.