Inside the Eaton fire mandatory evacuation zone in Altadena, technical crews have joined the ranks of police officers and firefighters. A traffic signal electrician from the Los Angeles County Public Works was checking every signal the county maintains. So far, he said, the damages he had seen were not too extensive.

The University of California, Los Angeles, will hold remote classes for undergraduate and graduate courses through the end of next week, the chancellor announced. Employees who can work remotely are being asked to do so, too.

Local authorities asked the Bureau of Alcohol, Tobacco and Firearms to take the lead on investigating the cause of the Palisades fire, said Ginger Colbrun, a spokeswoman for the bureau’s Los Angeles field division. About 15 personnel from across the country are traveling to Los Angeles to join the investigation. It’s too early to say what might have caused the fire, Colbrun said.