SACRAMENTO, Calif. (AP) – Regulators say they have fined Pacific Gas and Electric Co. $8.3 million for failing to maintain a power line that sparked a massive blaze in Northern California that destroyed 549 homes and killed two people. The California Public Utilities Commission said Tuesday it fined PG&E $8 million for poor tree maintenance by PG&E and its contractors and the rest for failing to report one of its power lines may have started the blaze. A Cal Fire investigation found the state’s largest utility and its contractors failed to maintain a gray pine tree that slumped into a power line igniting the September 2015 fire in Amador County. The blaze burned for three weeks, killing two people and destroying more than 900 structures, including about 550 homes. The 110-square-mile fire caused an estimated $300 million in insured losses. It is the seventh-most destructive wildfire in California history.