Editing Proximate cause (section)

==Efficient proximate cause==
A related doctrine is the insurance law doctrine of '''efficient proximate cause'''.  Under this rule, in order to determine whether a loss resulted from a cause covered under an [[insurance policy]], a court looks for the predominant cause which sets into motion the chain of events producing the loss, which may not necessarily be the ''last'' event that immediately preceded the loss.  Many insurers have attempted to contract around efficient proximate cause through the use of "anti-concurrent causation" (ACC) clauses, under which if a covered cause and a noncovered cause join to cause a loss, the loss is not covered.

ACC clauses frequently come into play in jurisdictions where [[property insurance]] does not normally include [[flood insurance]] and expressly excludes coverage for floods.  The classic example of how ACC clauses work is where a [[hurricane]] hits a building with wind and flood hazards ''at the same time.'' If the evidence later shows that the wind blew off a building's roof and then water damage resulted only because there was no roof to prevent rain from entering, there would be coverage, but if the building was simultaneously flooded (i.e., because the rain caused a nearby body of water to rise or simply overwhelmed local sewers), an ACC clause would completely block coverage for the ''entire'' loss (even if the building owner could otherwise attribute damage to wind v. flood).

A minority of jurisdictions have ruled ACC clauses to be unenforceable as against public policy, but they are generally enforceable in the majority of jurisdictions.<ref>''Leonard v. Nationwide Mut. Ins. Co.'', 499 F.3d 419 (5th Cir. 2007) (surveying cases).</ref>