Passage 2.21.10
τούτους δή φασιν Ἀργεῖοι τὸ ἐξ ἀρχῆς οἰκοδομῆσαι τῇ Λητοῖ τὸν ναόν· ἐγὼ δὲ---πρόσκειμαι γὰρ πλέον τι ἢ οἱ λοιποὶ τῇ Ὁμήρου ποιήσει---δοκῶ τῇ Νιόβῃ τῶν παίδων μηδένα ὑπόλοιπον γενέσθαι. μαρτυρεῖ δέ μοι τὸ ἔπος τὼ δʼ ἄρα καὶ δοιώ περ ἐόντʼ ἀπὸ πάντας ὄλεσσαν. Hom. Il. 24.609 οὗτος μὲν δὴ τὸν οἶκον τὸν Ἀμφίονος ἐκ βάθρων ἀνατραπέντα οἶδε·
The Argives indeed say that these were the ones who first built the temple of Leto. But I—for I attach somewhat greater importance than others to the poetry of Homer—believe that none of Niobe's children survived. Homer’s verse, "But they destroyed the two remaining though they were among many others," confirms my opinion. Homer indeed knows well that the house of Amphion was utterly overthrown from its foundations.