Investigators are considering an array of possible ignition sources for the huge fires that have killed at least 10 people and destroyed thousands of homes and businesses in the Los Angeles area. In hilly Pacific Palisades, officials have placed the origin of the wind-whipped blaze behind a home on Piedra Morada Drive above a densely wooded arroyo. Lightning is the most common source of fires in the U.S., according to the National Fire Protection Association. But investigators ruled that out quickly: There were no reports of strikes in that area or near the second major blaze, the Eaton fire. The next two most common causes are fires intentionally set, and those sparked by utility lines.
