MIDDLETOWN -- Cal Fire says the cause of 2015's destructive Valley Fire was faulty hot tub wiring.
The Valley Fire, which began Sept. 12 and was contained just over a month later, burned 76,067 acres in Lake, Napa and Sonoma counties. It's said to be the third most destructive wildfire in California history.
Four people were killed, and 1,281 homes were among the structures that burned. Cal Fire says firefighting efforts cost $57 million.
Investigators say the homeowner admitted that he installed the wiring that was later found to not be up to code. It was not immediately known if charges would be filed.