N.C. Gen. Stat. § 31-52: Acts and events of independent significance.

A will may dispose of property by reference to acts and events that have significance apart from their effect upon the disposition made by the will, whether they occur before or after the execution of the will or before or after the testator's death. These acts and events may include the execution or revocation of another individual's will and the safekeeping of items in a secured depository. (2007-184, s. 2.)