Federal officials have initiated a criminal investigation into PG&E Corp.’s potential role in starting California’s largest wildfire of the year.

On Sept. 24, the US Forest Service removed one of the utility’s transmission poles from the site in Placer County where the Mosquito fire started, PG&E said Monday in a filing. USFS didn’t immediately respond to inquiries about the probe.

Thousands of residents were under evacuation and shelter-in-place orders early Tuesday after heavy rains unleashed mudslides in a mountain area east of Los Angeles that burned two years ago, sending boulders and other debris across roads.

Firefighters went street by street in the community of Forest Falls Monday night to make sure no residents were trapped. Eric Sherwin, spokesperson for the San Bernardino County Fire Department, said crews hadn’t found anyone who needed to be rescued and no one was reported missing. Crews would canvas the neighborhoods again and begin cleanup efforts after sunrise, he said.

Californians stepped up their water conservation in July, using 10.4% less than two years ago as the state struggles with a years-long drought, state water officials said.

July marks the first full month that new conservation rules like a ban on watering decorative grass were in effect, which state water officials said helped make a difference. Water use started to trend down in June after a bump in April and May.

Still, conservation over the past year is still far below the 15% drop Gov. Gavin Newsom requested in summer 2021 as the state fought to maintain critical water supplies in anticipation of a drier year ahead. Statewide, water use is down since then by just 3.4% compared with 2020, the year Newsom is measuring against.

A wood products company said that it is investigating whether a fire that killed two people as it swept through a Northern California town was caused by the possible failure of a water-spraying machine used to cool ash at its veneer mill.

Roseburg Forest Products Co. also announced that although the investigation was not complete, it was planning to provide up to $50 million for a community restoration fund.

The Mill Fire erupted Sept. 2 at the company’s facility in the small town of Weed on Interstate 5, about 280 miles northeast of San Francisco.

California is facing a prolonged late-summer heat wave this week, with widespread triple-digit temperatures starting in the south and spreading northward, the National Weather Service said Monday.

Excessive heat watches will go into effect Wednesday morning and remain in effect through Sunday evening in a large swath of Southern California, including much of the normally temperate coastline, forecasters said.

Temperatures were predicted to top 100 degrees (37.7 Celsius) in many valley and mountain locations.

“This heat may be record breaking and will likely produce a very high heat illness risk,” the Los Angeles-area weather office wrote.

The main highway from Los Angeles to Phoenix was damaged by a flash flood that washed out part of the road through the Southern California desert in the latest bout of punishing monsoonal thunderstorms that have hit the region this summer.

The newest round of flooding started Wednesday evening, damaging a roadway that was part of a detour past a repair project along eastbound Interstate 10 near the small community of Desert Center, about 165 miles east of Los Angeles.

Traffic in both directions was halted initially, but westbound lanes for motorists heading from Arizona to California reopened later.

The McKinney Fire in Northern California was still out of control on Wednesday despite cloudy, cooler conditions on Tuesday night.

The fire has burned nearly 90 square miles since it started on Friday in an unpopulated area in Klamath National Forest.

CalFire listed the blaze as 0% contained as of Wednesday afternoon, unchanged from its level of containment on Monday.

Multiple evacuation orders and warnings have remained in effect since Monday.

Wildfires in California and Montana exploded in size overnight amid windy, hot conditions and were quickly encroaching on neighborhoods, forcing evacuation orders for over 100 homes Saturday, while an Idaho blaze was spreading.

In California’s Klamath National Forest, the fast-moving McKinney fire, which started Friday, went from charring just over 1 square mile to scorching as much as 62 square miles by Saturday in a largely rural area near the Oregon state line, according to fire officials. The fire burned down at least a dozen residences and wildlife was seen fleeing the area to avoid the flames.

A destructive wildfire near Yosemite National Park burned out of control through tinder-dry forest on Sunday and had grown into one of California’s biggest blazes of the year, forcing thousands of residents to flee remote mountain communities.

Some 2,000 firefighters battled the Oak Fire, along with aircraft and bulldozers, facing tough conditions that includes steep terrain, sweltering temperatures and low humidity, according to the California Department of Forestry and Fire Protection, or Cal Fire.

“It’s hot out there again today,” Cal Fire spokesperson Natasha Fouts said Sunday. “And the fuel moisture levels are critically low.”