70.720.  Casualty reserve fund, created, source of funds, uses. — 1.  The "Casualty Reserve Fund" is hereby created.  It is the fund in which shall be accumulated the contributions made by employers for pensions either to be paid members who retire on account of disability or that result from a member's death that was the natural and proximate result of a personal injury or disease arising out of and in the course of his or her actual performance of duty as an employee, and from which shall be made transfers as provided in sections 70.600 to 70.755.

  2.  When paid to the system, the employer contributions provided for in subsection 4 of section 70.730 shall be credited to the casualty reserve fund.

  3.  When a disability allowance or an allowance that results from a member's death that was the natural and proximate result of a personal injury or disease arising out of and in the course of his or her actual performance of duty as an employee first becomes due and payable, there shall be transferred to the benefit reserve fund from the casualty reserve fund an amount equal to the reserve for the allowance, minus:

  (1)  The accumulated contributions, standing to the member's credit in the members deposit fund at the time the allowance first becomes due and payable; and

  (2)  The accrued service pension reserve determined pursuant to subsection 5 of section 70.710.