Cal. GOV § 850.6

(a) Whenever a public entity provides fire protection or firefighting service outside of the area regularly served and protected by the public entity providing that service, the public entity providing the service is liable for any injury for which liability is imposed by statute caused by its act or omission or the act or omission of its employee occurring in the performance of that fire protection or firefighting service. Notwithstanding any other law, the public entity receiving the fire protection or firefighting service is not liable for any act or omission of the public entity providing the service or for any act or omission of an employee of the public entity providing the service; but the public entity providing the service and the public entity receiving the service may by agreement determine the extent, if any, to which the public entity receiving the service will be required to indemnify the public entity providing the service.

(b) Notwithstanding any other provision of this section, any claims against the state shall be presented to the Department of General Services in accordance with Part 3 (commencing with Section 900) and Part 4 (commencing with Section 940) of Division 3.6 of Title 1.