If any member of such fire department shall, while in the performance of his duty, be killed or die as the result of an injury received in the line of his duty, or of any disease contracted by reason of his occupation as fireman, or shall die from any cause whatever while in such service, and shall leave a widow, or child or children under the age of sixteen years, surviving, said board of trustees shall direct the payment from said pension fund monthly to such widow, while unmarried, such sum of money as may be determined by the rules and regulations provided for the management of such funds, and said board shall also direct the payment out of said pension fund for each child until it reaches the age of sixteen years such sum of money as may be determined by said rules and regulations, and in case the party suffering such disability is a member of the volunteer department, the amount to be paid monthly to his widow and children aforesaid shall be fixed by said board of trustees. If there be no widow, or if such widow die while unmarried, the amount of her said benefits may be added to the said benefits for such children. If any member of the fire department shall die from any cause while a member of such department, but not while in the service thereof, if he be married his widow and children shall receive from the pension fund the same benefits as are payable from the pension fund in other cases, and if he be unmarried his dependent father, mother, brothers and sisters shall receive from the pension fund the same benefits as are payable from said fund in other cases.