Hot on the Trail of Fires

The 6,000-acre Santa Clarita wildfire, which finally appeared to be under control Monday, didn’t start with a match or a dropped cigarette. In fact, it didn’t start with a human at all.

As best we can tell, it began when a red-tailed hawk landed on a utility wire, was electrocuted and fell burning to the ground. Plants caught fire and that fire quickly spread, resulting ultimately in the evacuation of hundreds of homes.

All because of a bird, you might say. Yet this scenario isn’t as uncommon as you would think. Every fire, no matter how big, has a point of origin -- the place where it started. Fire investigators, trained in finding the clues left behind, first must locate the point of origin. From there, they are able to determine the fire’s cause from the indicators they see -- things like which way the burned grass has fallen. When grass burns, it falls toward the fire (the stalk burns first).

In this case, fire investigators found the point of origin in very close proximity to a power pole. And nearby was a charred red-tailed hawk, its body rigid, suggesting that it had been electrocuted before being burned.

Fire investigators look first for natural causes. Was there a recent lightning storm? Did a bolt strike a tree and ignite it? Or, as in this case, was there a dead bird near a power pole?

When they exhaust the natural causes, they next turn to human causes. Are there cigarette butts on the ground? Was someone in the area using a chain saw or barbecuing?

If you rule those out, you think arsonist. There are no “arson investigators”; we just investigate the cause of fires -- arson is one of many possible causes. We have an arsenal of tools. Sometimes we use dogs trained to sniff out accelerants. But most of the work is just down-and-dirty digging.

In this case, the evidence was easy to interpret. The point of origin was not in an area near people. Access from the road was limited. There was a power pole nearby and a dead bird totally cooked from electrocution.

The one unusual aspect is that the bird was a red-tailed hawk, a bird with a smaller wingspan than the typical suspects. Generally, the bigger birds, like turkey vultures and condors -- both with bigger wingspans -- set off electrocutions and fires.

As long as the birds are only touching one wire, they are OK. But if, when they raise their wings, one wing comes in contact with another power line, they are electrocuted. They burst into flames, fall to the ground and can ignite the brush.

It’s true that humans have to be careful in the forest with matches, cigarettes and campfires. Electrical wires can be a problem too.

But fire is also a natural thing. It’s Mother Nature’s way of cleaning out the forests. If fires didn’t threaten people and houses, we’d rather let them burn.

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Capt. Jim Dellamonica is a spokesman for the California Department of Forestry and Fire Protection. This article is excerpted from an interview with The Times.