Wash. Rev. Code § 51.04.010
The common law system governing the remedy of workers against employers for injuries received in employment is inconsistent with modern industrial conditions. In practice it proves to be economically unwise and unfair. Its administration has produced the result that little of the cost of the employer has reached the worker and that little only at large expense to the public. The remedy of the worker has been uncertain, slow and inadequate. Injuries in such works, formerly occasional, have become frequent and inevitable. The welfare of the state depends upon its industries, and even more upon the welfare of its wage worker. The state of Washington, therefore, exercising herein its police and sovereign power, declares that all phases of the premises are withdrawn from private controversy, and sure and certain relief for workers, injured in their work, and their families and dependents is hereby provided regardless of questions of fault and to the exclusion of every other remedy, proceeding or compensation, except as otherwise provided in this title; and to that end all civil actions and civil causes of action for such personal injuries and all jurisdiction of the courts of the state over such causes are hereby abolished, except as in this title provided.
RCW 51.04.010