SAN FRANCISCO — Pacific Gas & Electric, which is blamed for some of California's deadliest recent fires, knew for years that dozens of its aging power lines posed a wildfire threat but avoided replacing or repairing them, it was reported Wednesday. The Wall Street Journal, using company documents obtained under the federal Freedom of Information Act, reported that the utility told the U.S. Forest Service in 2017 and 2018 that 49 aging steel towers on one transmission line needed replacement and another 57 needed replacement of their hardware and aluminum lines. The Journal previously reported that PG&E delayed safety work on the line, known as the Caribou-Palermo line, for five years. State investigators said an equipment failure on that line sparked a November wildfire that essentially wiped out the Northern California town of Paradise and killed 85 people. It was the deadliest and most destructive in state history.