The widow or widower, child, children or beneficiary of any firefighter retired under this chapter shall receive an amount equal to his or her accumulated contributions to the fund, plus earned interest thereon compounded semiannually: PROVIDED, That there shall be deducted from said sum the amount paid to decedent in pensions and the remainder shall be paid to his or her widow or widower, child, children or beneficiary: PROVIDED FURTHER, That the amount paid shall not be less than one thousand dollars.