Death is prominent in this novel, especially senseless death in relation to acts of terrorism. The haunting image of death is ever-present in Keith’s mind, as well as in the thoughts of Keith’s friends who survived the attack. Having seen the destruction, the falling bodies, his crushed and burnt friends, Keith does not fear death but rather wonders what life is all about. In some ways, Keith’s thoughts of death are similar to those of the terrorists. The terrorists, in DeLillo’s interpretation, committed themselves to death for a cause they believed was for the better good. In this way, death takes on a different meaning. Death becomes a means to an end. Although Keith has no such commitment, death becomes something different after he has escaped the tower. Death has thrown Keith into a different world.  His world is one that he believes his wife to be incapable of understanding.  Only Florence, the woman who also escaped the towers, understands; or at least that is what Keith believes. Witnessing death has separated Keith from most people around him, as if Keith is living in a world somewhere in between.

Lianne reflects on a different form of death, the suicide of her father and the slow death that the Alzheimer’s patients face. The terrorist attacks bring death to the forefront of Lianne’s thoughts, but not in the same way it has affected Keith. Keith seems to want to let everything go, but Lianne is desperate to hold on. Lianne fears death—her own. She is afraid she might be dying slowly like those who are afflicted with Alzheimer’s or that she will become as depressed as her father and want to take her own life.

The Alzheimer’s patients epitomize the involuntary loss of memory. These men and women try hard to hold onto their memories. But Keith is torn between trying to forget and wanting to remember at the same time, creating a torturous limbo.

The actor who performs the Falling Man act by projecting himself off the sides of buildings definitely wants to remember and wants to make sure that everyone else remembers too. He wants people to remember the awful emotions they experienced when they saw the terrified people caught on the top floors. This actor has those memories stuck in his head. Jumping from the sides of buildings is the only way he can find relief. But even that does not help, because he must do it over and over again.

There are other memories mentioned, such as Martin’s background. Martin is a friend and lover of Lianne’s mother. Martin’s past includes acts that he does not want to talk about. It is suspected that Martin may have performed some acts of terrorism himself. That memory is buried but not forgotten. It is just not talked about. In a similar fashion, the terrorists must also bury memories. They must not think about their family and close friends. They must forget about all the identifying events that make up their lives. In order to do what they are about to do, they must completely wipe clean their histories.

Another theme is one that might be called “relationship”. It is not really a love relationship, but it is something that loosely binds people together. Keith and Lianne, for instance, are in a relationship that Lianne describes at one point as family. She wants them to be a family. She does not care how they define their relationship as long as she can count on Keith being with...