Adam Clarke on Luke 13:4

The tower in Siloam - This tower was probably built over one of the porticoes near the pool, which is mentioned Joh 9:7. See also Neh 3:15.

Debtors, οφειλεται, a Jewish phrase for sinners. Persons professing to be under the law are bound by the law to be obedient to all its precepts; those who obey not are reckoned debtors to the law, or rather to that Divine justice from which the law came. A different word is used when speaking of the Galileans: they are termed ἁμαρτωλοι, as this word is often used to signify heathens; see the notes on Luk 7:37; it is probably used here in nearly a similar sense. "Do ye who live in Jerusalem, and who consider your selves peculiarly attached to the law, and under the strongest obligations to obey it - do ye think that those Galileans were more heathenish than the rest of the Galileans, because they suffered such things? No. It was not on this account that they perished: both these cases exhibit a specimen of the manner in which ye shall all perish, if ye do not speedily repent, and turn to God."