Radak: Armon is a tall house. When its gates are closed, the only way to enter is via the windows, which is almost impossible for they are very high. Therefore, they do not close the windows; they are always open. Death ascended our windows, and entered our Armonos suddenly; we did not guard from it. Even though the true Nevi'im told us constantly, we did not heed them. It never crossed our minds that it will be, or if it will be, that it will be so great.

Malbim: In your lamentations, you depict as if death arose by itself, like a thief who sneaks in via the window, and from there to the Armon. (You err; refer to 9:21:1:2.)

Rashi: In the market, like "v'Chutzos Tasim Lecha b'Damesek" (Melachim I, 20:34). Radak - children normally play in the market, and adolescents in the streets. [Both] are cut off from there.