The Supreme Court in Baldwin v. State of California (1972), overruling its own prior precedent, held that the design immunity provided by section 830.6 was not perpetual, but was subject to loss under certain circumstances. In that case, involving an automobile accident caused by the absence of a left-turn lane in a 25 year-old intersection design where traffic had substantially increased, the court held that the statutory immunity could be lost where the public entity has actual or constructive notice that the plan or design has, under changed physical conditions, produced a dangerous condition of public property and the entity fails to act reasonably to correct or alleviate the hazard. (Baldwin, supra, 6 Cal. 3d at p. 434.) This result was justified, the court said, because the rationale for the grant of a design immunity had no relevance or application where actual post design experience has demonstrated the dangerous nature of the design. "Where experience has revealed the dangerous nature of the public improvement under changed physical conditions, the trier of fact will not simply be reweighing the same technical data and policy criteria which went into the original plan or design. Rather, there will then be objective evidence arising out of the actual operation of the plan--matters which, of necessity, could not have been contemplated by the government agency or employee who approved the design. No threat of undue interference with discretionary decision-making exists in this situation." (Baldwin, supra, 6 Cal. 3d at p. 435.) In 1979, the Legislature reacted to the Baldwin decision by amending section 830.6. That amendment added the second and third sentences to the section. It provides that notwithstanding notice to a public entity that improved public property no longer conforms with the approved design or no longer conforms to a standard that reasonably could be approved by the public entity: (1) design immunity continues for a reasonable period of time sufficient to allow the public entity to obtain funds for and complete remedial work; (2) if the public entity is unable to remedy the condition due to practical impossibility or lack of funds, design immunity continues as long as the public entity reasonably attempts to warn the public of the danger. (Stats. 1979, ch. 481, 1, p. 1638.) Thus, section 830.6, as so amended, specifies circumstances in which a public entity retains design immunity, but it does not specify the circumstances in which a public entity loses such immunity. (See Alvarez v. State of California (1999) 75 Cal. App. 4th 903, 912; Grenier v. City of Irwindale (1997) 57 Cal. App. 4th 931, 944.) For that we necessarily must also look to the decision in Baldwin. The legislative history of the 1979 amendment to section 830.6 indicates that it was "intended to respond to Baldwin by providing a reasonable extension of design immunity when, under Baldwin, that immunity otherwise would be lost." (Alvarez v. State of California, supra, 75 Cal. App. 4th at p. 912.) Baldwin and the 1979 amendment to section 830.6, read together, provide that design immunity can be lost to the defendant public entity if the plaintiff can establish three elements: (1) the approved plan or design has become dangerous by reason of a change in physical conditions; (2) the public entity has actual or constructive notice of the dangerous condition thus created; (3) the public entity has had a reasonable period of time to obtain the funds and carry out the necessary remedial work to bring the property back into conformity with a reasonable design or plan, or the public entity is unable to remedy the dangerous condition due to practical impossibility or lack of funds and does not reasonably attempt to provide adequate warnings. (Compton v. City of Santee (1993) 12 Cal. App. 4th 591, 598.)