Unless from the terms of the will the intent is clear and explicit to the contrary, and except as provided in section 633.273:
1. A devise, other than a residuary devise, that fails for any reason becomes a part of the residuary estate.
2. If the residuary estate is devised to two or more persons, the share of a residuary devisee that fails for any reason passes to the other residuary devisee or to the other residuary devisees in proportion to the interest of each in the remaining part of the residuary estate.