Neither the state, nor the office, nor any political subdivision thereof nor other agencies, nor, except in cases of willful misconduct, the agents, employees or representatives of any of them engaged in any civil defense, disaster or emergency and the planning or preparation for the same, or disaster or emergency relief activities, acting under proper authority, nor, except in cases of willful misconduct or gross negligence, any person, firm, corporation or entity under contract with them to provide equipment or work to be used in civil defense, disaster or emergency planning, preparation or relief, while complying with or attempting to comply with this act or any rule or regulation promulgated pursuant to the provisions of the act, shall be liable for the death of or any injury to persons or damage to property as a result of such activity. The provisions of this section shall not affect the right of any person to receive benefits to which he would otherwise be entitled under this act or under the worker’s compensation law or under any pension law, nor the right of any such person to receive any benefits or compensation under any act of congress.