Bava Kama3: 4
שְׁנֵי קַדָּרִין שֶׁהָיוּ מְהַלְּכִין, זֶה אַחַר זֶה, וְנִתְקַל הָרִאשׁוֹן וְנָפַל, וְנִתְקַל הַשֵּׁנִי בָרִאשׁוֹן, הָרִאשׁוֹן חַיָּב בְּנִזְקֵי הַשֵּׁנִי.
[If] two potters were walking, one after the other, and the first one stumbled and fell, and the second one stumbled over the first one, the first one is liable for the injuries of the second one.