Has anyone ever used a significant historical event to disappear? (WW2, war)

[The Continental]

In wars or tragedies when 100s or 1000s have died, has it ever been discovered that someone used that event to disappear with the assumption being that they too died?

[NJGOAT]

Certainly there are plenty of cases of this among Germans in WW2, in particular those who knew they may be accused of war crimes, they would change their identity leaving people to think they died in the war and then attempt to live under an assumed/stolen identity. Probably the most famous cases are Eichmann and Mengele who both fled under assumed identities to South America.

Stories about this kind of thing are present in regards to every war though, from the Revolution and Civil Wars up to more modern conflicts. Maybe others can put up some stories that are less famous then the ones about Eichmann and Mengele and involving regular soldiers, which I think was the OP's intent.

[Grandstander]

Such an action is one of the foundational premises of the tv series "MadMen." The lead character, Don Draper, stole that identity from a dead US officer in the Korean War, and hid behind it in order to desert. Some of ths episode's plots have revolved around his nearly getting caught and exposed for who he really is.

[The Continental]

I was thinking more towards a specific event say D-Day or Titanic, but anything about a disappearance to later be revealed would suffice. The theories on Billy the Kid, Jesse James, and John Wilkes Booth are quite interesting.

[Mathguy]

Here is a list, one in particular meets your specifications....a guy used 9-11 as cover.

Faked death - Wikipedia, the free encyclopedia

[VM1138]

An older but very famous (among historians anyway) example is Martin Guerre, who used a battle in the Basque region to fake his death, only to return later to face a man who had been pretending for years to be him in his hometown and with his wife.