A law enforcement task force has been set up to uncover what caused the fires. The local agencies involved — the Los Angeles fire and police departments and the county Sheriff’s Department, as well as Cal Fire — are considered to be among the most skilled in the country. The Bureau of Alcohol, Tobacco, Firearms and Explosives is leading the probe.

Across Los Angeles, a series of wildfires fanned by the powerful Santa Ana winds have been leveling homes in the area for nearly a week, leaving a path of record-breaking destruction in their wake. The largest of the fires,