…California is experiencing its worst fire season in memory, with one million acres burned so far this year, more than twice the amount in the same period last year — and with each new blaze Californians are asking themselves: How did this happen? The answer… is that destructive wildfires nearly always begin with a human being, either intentionally or by mistake. There are endless ways people start fires — a discarded cigarette, a child playing with matches, a campfire, fireworks, a car accident.  This year, even as firefighters battle one blaze after another across the state, investigators are already finding answers for how some of the fires started. One began with a spark from a flat tire. Another when someone hammered a fence post amid dry vegetation. Still another was allegedly ignited by a conspiracy-minded recluse who had sent a text message to a local firefighter warning the place “is going to burn.”