Finding coverage under the ensuing loss provision, the Washington Supreme Court overruled a Court of Appeals decision we previously reported here. Vision One, LLC v. Philadelphia Indem. Ins. Co., 276 P.3d 300 (Wash. 2012).

   Vision developed a condominium project. Before concrete was poured, a subcontractor supplied the shoring to temporarily support the poured concrete slabs. After the shoring installation was completed, concrete was poured on the first floor. When the pouring was finished, the shoring gave way. The framing, rebar and newly poured concrete came crashing down onto the the lower level parking area, where the wet concrete eventually hardened. It took several weeks to clean up the debris and repair the damage.

   Vision had a builders' risk policy with Philadelphia. The policy excluded losses caused by or resulting from deficient design or faulty workmanship. Collapse, however, was not listed as an excluded event. Further, the exclusion for faulty workmanship contained a resulting loss clause providing that "if loss or damage by a Covered Cause of Loss results, [Philadelphia] will pay for the loss or damage caused by that Covered Cause of Loss."

   Philadelphia denied coverage under the faulty workmanship exclusion. Vision sued, contending that if an excluded peril and a covered peril both contributed to the property damage, then the policy covered the loss. The trial court agreed. The trial court also determined that the shoring equipment was separate and distinct from the concrete, rebar and wood forms. Therefore, any resulting loss or damage caused by the concrete collapse was covered.

    The Court of Appeals reversed because the trial court had not properly applied the efficient proximate cause rule. The court also reversed on the resulting loss provision because it required a secondary covered peril to proximately cause an ensuing loss. The Court of Appeals found no secondary covered peril that triggered Vision's losses.

  The Supreme Court first analyzed the ensuing loss provision. Because Vision sought coverage for losses associated with the collapse of the floor resulting from faulty workmanship, the court considered whether "collapse" was covered under the policy. There was no exclusion in the all-risk policy for the peril of collapse. The Court of Appeals incorrectly reasoned that if faulty workmanship was the initial excluded peril, then the simultaneous collapse of the shoring and concrete slab was the loss. Had the collapse triggered a secondary covered peril, such as a fire, then damage caused by the fire would be a resulting loss. The Supreme Court determined this analysis failed to consider that collapse was a covered peril.

   The court next considered Philadelphia's argument that the case had to be remanded to determine whether the damages were caused by faulty workmanship. Philadelphia submitted that the resulting loss clause applied only if the jury found that faulty workmanship was the efficient proximate cause of the loss.

   Again, the Supreme Court disagreed. The efficient proximate cause rule applied only when two or more perils combined in sequence to cause a loss and a covered peril was the predominant or efficient cause of the loss. The efficient proximate cause rule mandated coverage, even if an excluded event appeared in the chain of causation that ultimately caused the loss. When, however, an excluded peril set in motion a causal chain that included covered perils, the efficient proximate cause rule did not mandate exclusion of the loss.

   Therefore, the trial court's judgment was reinstated. While the policy excluded losses caused by faulty workmanship, the ensuing loss clause covered the collapse damages.