Mishnayos Bava Basra Perek 9 Mishnah 8

A house collapsed on a son and upon his father, or upon a certain person and upon those from whom he stands to inherit, and it is unknown who died first. If the son bore the responsibility to pay the marriage contract of his wife and to pay a creditor, and the son had no money with which to pay them except that which he might inherit from his father, and the father’s heirs say: The son died first and afterward the father died, and therefore the son did not inherit property from his father, and the creditors say: The father died first and afterward the son died, resulting in the son’s inheriting his father’s property, enabling the creditors to collect payment from the property even after the son’s death, there is a dispute with regard to how to rule. Since it cannot be determined who died first, Beit Shammai say: They divide the property between them so that the father’s heirs receive half of his property and the son’s creditors receive the other half. And Beit Hillel say: The property retains its previous ownership status. Since the last known owner of the property was the father, the property is given to the father’s heirs.

נָפַל הַבַּיִת עָלָיו וְעַל אָבִיו אוֹ עָלָיו וְעַל מוֹרִישָׁיו, וְהָיְתָה עָלָיו כְּתֻבַּת אִשָּׁה וּבַעַל חוֹב, יוֹרְשֵׁי הָאָב אוֹמְרִים, הַבֵּן מֵת רִאשׁוֹן וְאַחַר כָּךְ מֵת הָאָב, בַּעֲלֵי הַחוֹב אוֹמְרִים, הָאָב מֵת רִאשׁוֹן וְאַחַר כָּךְ מֵת הַבֵּן, בֵּית שַׁמַּאי אוֹמְרִים, יַחֲלֹקוּ. וּבֵית הִלֵּל אוֹמְרִים, נְכָסִים בְּחֶזְקָתָן: