[Effective until July 1, 2021, this section will read:]
The liability of an employer to pay compensation shall be exclusive and in place of all other liability of such employer to the employee, his legal representative, husband or wife, parents, dependents, next-of-kin, and anyone otherwise entitled to recover damages at common law or otherwise from such employer on account of such injury or death, except that if an employer fails to secure payment of compensation as required by this chapter, an injured employee, or his legal representative in case death results from the injury, may elect to claim compensation under this chapter, or to maintain an action at law for damages on account of such injury or death. In such action the defendant may not plead as a defense that the injury was caused by the negligence of a fellow servant, nor that the employee assumed the risk of his employment, nor that the injury was due to the contributory negligence of the employee.