These are difficult and stressful days for Californians as a single spark could – and did – set off a conflagration that is hard to fathom. And the dire predictions are not over yet. Still no rain, and the grasses, shrubs and trees are suffering from a long drought that has left them tinder-dry. Along with low humidity and high winds, it’s the perfect prescription for disaster.
One huge fire was caused by a spark set off by a man with a hammer, working on a fence post in a field of dry vegetation. Another began at a backyard barbecue. A 2007 fire on Santa Catalina Island was ignited by workers cutting metal wires with a torch, reports The New York Times.
As investigators try to determine what started the most devastating wildfire in California history, which killed at least 56 people, the beginning premise is that human beings – through their mistakes, or their toys, tools and technologies – were probably behind it.
But looking into the cause of a fire, which can take months of painstaking work, also means rolling back the clock to a moment and to a spot that, like most of the town of Paradise, has been reduced to ash. What was there at the moment of the fire’s birth was probably destroyed by the fire itself, or at least profoundly altered.
Even a tiny pebble can be an important clue. On which side was it blackened by heat? What’s the condition of the soil below the fire at the place it started? An electrical charge from a high-voltage power line, for example, can solidify sand with a telltale signature. Then investigators look at things that were touched by the flames but not destroyed.
“If you’re looking at some trees, you look at the angle of char, the way that the needles froze in the heat; then you can say, ‘This fire spread from right to left,’” said James Engel, the deputy chief of law enforcement and fire prevention at the northern division of California Department of Forestry and Fire Protection, better known as Cal Fire.