Alone

 איכה ישבה בדד העיר רבתי עם היתה כאלמנה.  The opening of Eicha is not a possuk about the destruction but instead how Yerushalayim is left alone.  why is that the opening?  The Sfas Emes (Devarim 5653) explains that the loneliness is the separation of Yerushalayim from its parallel source above.  It is this divide, this separation that is the main lament, the opening remark of the navi.  The destruction is merely an outgrowth of that divide.  It is the loneliness, the sense of solitude, that is the main cry of the navi.