Ironically, despite the fact that the plot centralizes on a plane crash, the actual crash is the smallest of the disaster details. The theme of disaster is presented through several avenues.
First, there is the disaster to the family that the crash produces. Kathryn, the pilot's wife, and her teen-aged daughter Mattie must learn to grieve independently but still connect with each other through the loss of husband and father.
Every scene at Kathryn's house is painted as somewhat chaotic and disastrous, with the mixture of media crews outside and airline personnel inside. It is very difficult to know who to trust as things are very cryptic from the very beginning. The physical "disaster" of Kathryn's home mirrors the emotional disaster she feels and the mysterious disaster she slowly becomes aware of.
The final major disaster is of course the double life Jack was leading in Europe. As Kathryn unfolds the pieces of the mystery, she has an entirely new sense of grief to deal with. No longer is she only mourning the physical loss of her husband, but suddenly she is mourning the loss of a marriage relationship on a completely new level.