Firefighters in Pacific Palisades and Altadena have repeatedly been hampered by low water pressure and dry hydrants, revealing limitations in local water systems designed to supply neighborhoods.

Fire officials made the critical decision to forgo calling in scores of extra firefighters and equipment in the hours before the fire, according to internal documents reviewed by The Times.

Despite upgrades to wireless alerts system, emergency warnings were often ineffective when most needed during the Los Angeles wildfires. Some were sent to too many people, some to too few.