A fast-moving wildfire in northern Los Angeles County exploded mid-morning Wednesday, quickly growing from 50 acres to more than 5,000 acres in heavy brush near Castaic Lake. The fire has now closed all lanes of the busy Interstate 5 corridor in the Santa Clarita Valley,

The fire threat remains critical in Southern California, where thousands of residents were under evacuation orders Wednesday as fire crews battled the out-of-control Hughes Fire near Castaic, a suburb in the foothills and mountains of northern Los Angeles County.