Dozens of people are believed to have died in the Palisades and Eaton fires, which have burned down whole swaths of communities

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.

The hazardous air quality in Los Angeles is largely a result of smoke from the Pacific Palisades Fire, intensified by strong Santa Ana winds.