Los Angeles fire how it started: Authorities may have found main responsible factor for deadly wildfire

Los Angeles fire rather wildfire has ravaged parts of the iconic city in the US. While authorities still don’t know what sparked the deadly fires in the Los Angeles area, they do know one clear way the flames have spread: embers.

At least 24 people have died in the fires that have destroyed more than 12,000 structures since starting last Tuesday. The flames have been fueled by strong winds, which not only aid combustion by increasing the oxygen supply but carry embers to unburned areas.

Contrary to popular belief, experts say most homes destroyed by wildfires aren’t overcome by a racing wall of flames, but rather burn after being ignited by airborne embers.

What is an Ember?

An ember is a piece of burning debris. Once it becomes airborne, the more technical term is firebrand, said James Urban, an assistant professor in the Department of Fire Protection Engineering at Worcester Polytechnic Institute.

"If it's a wildland fire, it's typically pieces of wood or other types of vegetation that are burning," he said. "But when you have a fire that's burning through an urban area, it can be vegetation, it can be pieces of the house, it can be almost anything that burns," he said.

They can range in size from tiny specks to larger chunks.

Ember - How Deadly it is?

While many people might have seen stray embers rise from a campfire and even had one land on them, the embers involved in wildfires are drastically different, said Anne Cope, chief engineer at the Insurance Institute for Business & Home Safety.

Wind allows embers to burn harder and release more energy, becoming a more potent ignition source, Urban said. The firebrands then accumulate and sort of work together, gathering between the slats of wood fences or in shrubbery and igniting new fires.

In 2017, embers blew across a six-lane highway in Northern California, igniting businesses and then jumping from house to house in the Coffey Park neighborhood in Santa Rosa.

How are Researchers Studying Embers?

Together with San José State University, Worcester Polytech is part of a Wildfire Interdisciplinary Research Center. With funding from the U.S. Forest Service and National Science Foundation, researchers are examining how firebrands are produced and how that knowledge can be incorporated into models about how wildfires spread and defensive measures that can be applied to homes, Urban said. For example, his students have conducted experiments to see how vegetation management around buildings might affect how quickly a fire spreads between structures.

FAQs

Q1. How many people have killed?
A1. 24 people have died in Los Angeles wildfire.

Q2. How deadly are embers?
A2. While many people might have seen stray embers rise from a campfire and even had one land on them, the embers involved in wildfires are drastically different, said Anne Cope, chief engineer at the Insurance Institute for Business & Home Safety.