Firefighters working in searing weather struggled to contain a Northern California wildfire that continued to grow Sunday and forced the temporary closure of a major highway, one of several large blazes burning across the U.S. West amid another heat wave that shattered records and strained power grids. In Arizona, two firefighters died Saturday after a plane they were in crashed during a survey of a small wildfire in rural Mohave County. The Beech C-90 aircraft was helping perform reconnaissance over the lightning-caused Cedar Basin Fire, near the tiny community of Wikieup, when it went down around noon. The two firefighters were the only people on board. Officials identified one of them as Jeff Piechura, a retired Tucson fire chief who was working for the U.S. Forest Service. The name of the other was withheld until relatives could be notified. The National Transportation Safety Board is investigating the crash. In California, …