Cal Civ Code 1714.5(a)
Liability: Buildings and Premises
The State or a county, city, or other political subdivision who owns or maintains a building or premise that has been designated as a shelter, mass care center, first aid station, temporary hospital, or other necessary facility for minimizing the effects of a natural, man-made, or war-caused emergency will not be held legally responsible for injuries caused while on, or related to the use of, the premises. They can be held legally responsible if acting with intent to cause harm.
Liability of owner of premises designated as emergency shelter; Liability of disaster service workers
(a) There shall be no liability on the part of one, including the State of California, county, city and county, city or any other political subdivision of the State of California, who owns or maintains any building or premises which have been designated as a shelter from destructive operations or attacks by enemies of the United States by any disaster council or any public office, body, or officer of this state or of the United States, or which have been designated or are used as mass care centers, first aid stations, temporary hospital annexes, or as other necessary facilities for mitigating the effects of a natural, manmade, or war-caused emergency, for any injuries arising out of the use thereof for such purposes sustained by any person while in or upon said building or premises as a result of the condition of said building or premises or as a result of any act or omission, or in any way arising from the designation of such premises as a shelter, or the designation or use thereof as a mass care center, first aid station, temporary hospital annex, or other necessary facility for emergency purposes, except a willful act, of such owner or occupant or his or her servants, agents or employees when such person has entered or gone upon or into said building or premises for the purpose of seeking refuge, treatment, care, or assistance therein during destructive operations or attacks by enemies of the United States or during tests ordered by lawful authority or during a natural or manmade emergency.