I found it useful this year, while reading Eichah, to keep in mind that the events which are mentioned in it are/were presumably well-known to the intended audience.
This is certainly true for chapter 5, which is one long speech to God; and for large chunks of chapter 1 which are also addressed to God. These chapters give many examples of our suffering, despite the fact that God clearly knows about them already. It seems to me that this serves to create a sense of urgency. Chapter 5 in particular is simply a prayer from us to God - I found it spiritually productive to go off by myself and say it as a prayer, the same way I had said Shemoneh Esreh a couple hours earlier - and the mention of each event serves to make the argument sharper and more poignant. "Look. We have been suffering terribly. We have had to deal with X, and Y, and Z. We cannot bear it any more. Please return to us."
Chapters 2 and 4 seem to be addressed not to God but to some subset of the Jewish people, who, however, are intimately aware of what has happened. They call for specific responses to the tragedy: in chapter 2, calling out to God; in chapter 4, theological perspective.
(Chapter 3 is more complex, less nationally oriented, and more private. Eichah as a whole has a chiastic structure - chapters 1 and 5 are speeches to God, 2 and 4 are speeches to Israel, 3 is sort of an internal monologue.)
We are mostly accustomed to look at Eichah as a piece of history - if you want to know what the destruction was like, go read Eichah. I think that is the wrong approach. Chapters 1, 2, 4, and 5 take the form of public speeches. But they fail as speeches unless the events they describe are painfully familiar to the audience. We can read about our historical tragedies in Sefer Melachim, in Josephus, in books on the Holocaust, or wherever else. We thus obtain mental associations which come into play when we read Eichah. Eichah does not simply tell us about tragedies. It also tells us how to respond to them. And the goal of Tisha Beav is for us to begin responding.