Cal Fire sent out a press release Thursday morning stating PG&E is not to blame for the start of the fire.
Instead, it was a "private electrical system adjacent to a residential structure," the statement said.
Investigators did not identify any violations of California State law.
You can read the full press release here.
The Tubbs Fire destroyed more than 5,000 structures, burned more than 36,000 acres and killed 22 people.
MORE: Most destructive wildfires in California history
Most destructive California wildfires in history