In Sabella v. Wisler (1963) 59 Cal.2d 21, a builder constructed a home on inadequately compacted ground. The inadequate compaction caused the sewer pipe to break, and the water leaking from the sewer pipe, in conjunction with heavy rainfall during one season, caused the home's foundation to settle unevenly. The insurer denied the homeowners' claim based on the policy's exception for "'settling, cracking, shrinkage, or expansion of pavements, foundations, walls, floors or ceilings . . . .'" (Sabella, at p. 30.) The California Supreme Court, however, determined the efficient proximate cause of the loss was the builder's negligence, a cause not excepted from coverage under the policy. The court cited with approval an insurance treatise which explained: "'In determining whether a loss is within an exception in a policy, where there is a concurrence of different causes, the efficient cause -- the one that sets others in motion -- is the cause to which the loss is to be attributed, though the other causes may follow it, and operate more immediately in producing the disaster.'" (Id. at pp. 31-32.) In sum , a ruptured sewer line emptied water into the negligently constructed foundation of plaintiffs' home. As a result, the plaintiffs' home settled to uneven elevations to such an extent the foundation and walls cracked. The plaintiffs' insurance policy agreed to insure against all risks of physical loss except as provided in its exclusion section, which did not insure against loss caused by settling, cracking, or expansion of foundations, walls, or floors. The insurance company argued it was not liable for coverage since the cause of the loss was the settling and cracking. The California Supreme Court held the efficient proximate cause of the loss was the ruptured sewer line attributable to third party negligence (a covered peril) rather than settling or cracking (excluded perils). It further held an insurer cannot escape liability under section 532 where a covered peril is the efficient proximate cause of the loss just because an excepted peril is in the chain of causation. (Sabella v. Wisler, supra, 59 Cal. 2d at page 33.)