904. Liability for compensation
(a) Every employer shall be liable for and shall secure the payment to his employees of the compensation payable under sections 7, 8, and 9 [33 USC 907, 908, 909]. In the case of an employer who is a subcontractor, only if such subcontractor fails to secure the payment of compensation shall the contractor be liable for and be required to secure the payment of compensation. A subcontractor shall not be deemed to have failed to secure the payment of compensation if the contractor has provided insurance for such compensation for the benefit of the subcontractor.
(b) Compensation shall be payable irrespective of fault as a cause for the injury.