A home is engulfed in flames during the Eaton fire in the Altadena area of Los Angeles County.Josh Edelson/AFPThe Los Angeles firestorms show how quickly wildfires can turn into urban fires.Flying embers, not direct flames, often ignite homes first.Homeowners can mitigate fire risk by maintaining a clear perimeter around their properties.The firestorms razing Los Angeles show how quickly wildfires can turn into devastating urban conflagrations.Two fire management experts say there's a common misunderstanding about how homes ignite under these conditions.