More than 12,000 homes, businesses, schools and other structures have been destroyed by raging wildfires that began ripping through the Greater Los Angeles area last Tuesday.

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.

Crews are still battling deadly wildfires that broke out nearly a week ago in Los Angeles, with wind and dry conditions hampering the effort. Follow for live updates.