
    Deborah J. Pollock, an Infant, by Eugene C. Klein, the Guardian of Her Property, Respondent, v Marvin Pollock, Appellant.
   Order, Supreme Court, New York County, entered November 3, 1975, unanimously modified, on the law, to the extent of denying summary judgment striking the first affirmative defense, and, as modified, affirmed, without costs and without disbursements. In this action for declaratory judgment, plaintiff, guardian of the property of the infant, seeks a judgment declaring the validity of a separation agreement with respect to its provisions for child support. The separation agreement was entered into by the infant’s father, defendant herein, and the infant’s mother, deceased. Defendant asserts, as his first affirmative defense, that the separation agreement’s provision for child support terminated upon the death of the infant’s mother, the custodial parent. The child will reside with her maternal grandparents. The separation agreement did not include the mother’s death in the grounds specified for termination of child support. However, upon the mother’s death, custody of the child automatically reverts to the father, providing he is not unfit (Matter of Thorne, 240 NY 444; People ex rel. Boulware v Martens, 232 App Div 258, affd 258 NY 534). Upon the death of the custodial parent, the obligation for child support derived from the separation agreement ceases and the common-law duty of the natural parent to provide support is immediately revived (Matter of De Saulles, 101 Misc 447, 459-460). Defendant’s first affirmative defense is viable and goes to the merits of this action. Concur—Murphy, J. P., Lupiano, Birns, Capozzoli and Nunez, JJ.  