Irony, and the Irony that something is Ironic

In the book And Then There Were None by Agatha Christie, the following poem appears to foreshadow the series of murders that occur throughout the novel:


Ten little Soldier boys went out to dine;
One choked his little self and then there were nine.

Nine little Soldier boys sat up very late;
One overslept himself and then there were eight.

Eight little Soldier boys traveling in Devon;
One said he'd stay there and then there were seven.

Seven little Soldier boys chopping up sticks;
One chopped himself in halves and then there were six.

Six little Soldier boys playing with a hive;
A bumblebee stung one and then there were five.

Five little Soldier boys going in for law;
One got in Chancery and then there were four.

Four little Soldier boys going out to sea;
A red herring swallowed one and then there were three.

Three little Soldier boys walking in the zoo;
A big bear hugged one and then there were two.

Two Little Soldier boys sitting in the sun;
One got frizzled up and then there was one.

One little Soldier boy left all alone;
He went out and hanged himself and then there were none.

This poem expresses three levels of irony.
1. It’s ironic that all the deaths are made to seem accidental, or self-inflicted.  The child-like language and simple rhyming pattern adds to this. This seems ironic because it is obvious that the deaths will all be murders, against the wishes of the victims.  It is implied that the murderer of these people believes that because they have done wrong, they have already condemned themselves.  This obviousness disconnect between the murderer and the victims is realized by all, but the victims are hapless to stop the murders.
2. The meaning of how the victims were unable to stop being murdered is a metaphor for how the victims were also unable to stop themselves from killing: although they express regret and admit to their roles in the murders, none of the victims could help themselves. This is ironic because the murderer’s poem contradicts itself slightly, which is only known to the reader.
3. Finding irony in this novel.  The murderer is confident, and attributes his/her murders to justice.  It’s ironic then that justice (something that is crucial and serious) is the source of the black-humor in this book.