If a building collapsed on someone [on the Sabbath, and] it is uncertain whether he is there or not, [or] it is uncertain whether he is alive or dead, [or] it is uncertain whether he is a heathen or a Jew, they [must] clear the heap [of debris] for him. If they found him alive, they [must] clear [the rest of the debris] for him, but if he is dead they leave him [there].