In their probe of last summer's devastating Dixie Fire, California fire investigators have faulted PG&E utility, referring the matter to local prosecutors.

The fire, which began July 13, burned nearly 1 million acres, destroyed 1,329 structures and left an additional 95 damaged.

The California Department of Forestry and Fire Protection, also known as Cal Fire, announced Tuesday that investigators determined the blaze was caused by electrical distribution lines owned and operated by PG&E making contact with a tree west of the Cresta Dam in the northern part of the state.

Cal Fire said in its statement that it has forwarded its investigative report to the Butte County District Attorney's Office. The department referred questions to the prosecutor's office, which was not available for comment Tuesday evening.

PG&E responded with a statement reiterating remarks made by company officials in July that the tree that struck the line was one of eight million trees within striking distance of the utility's lines. The utility also said it has committed to burying 10,000 miles of lines, which it called "a bold step forward," along with other mitigation steps.

"Regardless of today's finding, we will continue to be tenacious in our efforts to stop fire ignitions from our equipment and to ensure that everyone and everything is always safe," the statement said.

Greenville Rubble from Dixie Fire
California state investigators determined Tuesday that utility company PG&E was at fault for the massive Dixie Fire, which burned nearly 1 million acres and forced multiple towns to evacuate. Justin Sullivan/Getty Images

Over the summer, the Dixie Fire grew to California's second-largest wildfire, spreading to five counties in the north-central part of the state. The size of the blaze came close to overcoming 2020's August Complex fire, which is the state's largest at 1.3 million acres.

The Dixie Fire leveled several mountain towns in Sierra Nevada counties, including Greenville and Grizzly Flats, before officials finally declared it to be fully contained in October with the arrival of winter storms.

PG&E is an investor-owned utility that serves about 16 million people throughout a 70,000-square-mile service area, according to its website. Cal Fire's determination isn't the first time PG&E has come under scrutiny for its role in wildfires.

In November, PG&E settled with state regulators over the 120-acre Kincade Fire in 2019 that was caused by its decommissioned but still energized transmission equipment that broke and ignited nearby vegetation. The utility agreed to pay $40 million to the state's general fund and another $85 million to remove abandoned transmission equipment over the incident.

In September, the utility was charged with manslaughter by the Shasta County District Attorney's Office in the Zogg Fire that killed four and burned nearly 200 homes near Redding in 2020.

PG&E filed for bankruptcy in 2019 and pleaded guilty to 84 counts of involuntary manslaughter related to the 2018 Camp Fire, which was sparked by its equipment and completely scorched the town of Paradise.

Over the summer, PG&E said it would bury 10 percent, or 10,000 miles, of its power lines at a cost of $15 billion to $30 billion to prevent wildfires.

Update 01/05/22, 6 p.m ET: This article has been updated to include a statement from PG&E.