Last Survivor Suicide

One little Indian boy left all alone

He went and hanged himself, and then there were none.

—Agatha Christie, And Then There Were None

Tragedy (or Black Comedy) wouldn't be the same without a final death to close the series of murders. When the last character doesn't find death on the battlefield or by the hands of their nemesis, they can still kill themselves to ensure drama and catharsis.

Note that this trope applies both if the survivor is a victim or is the murderer.

See also Driven to Suicide, Anyone Can Die (when they actually do) and Gotta Kill Em All. Can be part of a Thanatos Gambit. A Kill Them All story might end this way. Sometimes triggered by Better to Die Than Be Killed, or by Survivor Guilt. If the suicide attempt fails, then we have a Sole Survivor.

For the Real Life examples, follow the Rule of Cautious Editing Judgment very strictly.

As a Death Trope, Spoilers ahead may be unmarked. Beware.

Examples of Last Survivor Suicide include:

Anime and Manga

The last character to die in Death Note, Misa Amane, commits suicide.
The last remaining character on Basilisk kills himself, leaving the samurai to sort out the resulting mess.
Several examples from Higurashi no Naku Koro ni. Onikakushi-hen ends with Keiichi's suicide after murdering Mion and Rena, while Watanagashi-hen ends with Shion's accidental death/suicide.
- Tatarigoroshi-gen's Visual Novel version explains that after the Hinamizawa Disaster, only Kasaii, Shion and Keiichi were left. After Kasaii's death (from inhalation of fumes during the disaster), Shion committed suicide, and several months later, Keiichi (now in a mental hospital) also commits suicide.
In the Detective Conan, "Moonlight Sonata Murder Case", the murderer tries to invoke the trope by trying to make it look like their last murder victim was in fact the murderer and committed suicide instead of being murdered. When the identity of the real murderer is revealed, the real murder commits suicide.

Comics

Frank Castle at the end of Punisher Kills The Marvel Universe.

Film

The Last Samurai ends with the assisted suicide/seppuku of Katsumoto, who is either the last or the penultimate samurai, depending on whether you count the American Nathan Algren.
Not shown but strongly implied in the movie version of CLAMP's "X" (the manga and the series left much more people alive).
Averted in the movie version of The Mist: Driving through the endless mist, thinking that everything is hopeless, the characters decide to commit suicide. The protagonist takes a gun and methodically shoots everyone in the car, including his own son. Last, he turns the gun on himself... only to realize that he's out of bullets.

Literature

And Then There Were None uses this trope twice. First, after witnessing the murder of her companions of misfortune, Vera Claythorne finally snaps and hangs herself out of guilt, thus completing the series of deaths with a suicide, following the original rhyme. Then it becomes clear that the murderer was still alive after her death, but the trope is finally played straight once again because U.N. Owen kills himself too in the end.
- Of course, the nursery rhyme provides the page quote.
Brave New World: John the Savage hangs himself, and the novel closes on his corpse being found.

Live Action TV

The X-Files: The last of a group of astronauts who had been traumatized during their mission chooses to kill himself after various gruesome deaths (including other suicides) take out the rest of them.
Criminal Minds episode "Reckoner" played with this trope. A Hanging Judge organized the murders of some Karma Houdinis that had managed to evade justice, and put his own name on the list because he was going to die anyway of cancer. In the end, he didn't kill himself but was sniped by the mobster he had hired to kill the other victims.
In The Walking Dead, there is only one surviving scientist left at the CDC headquarters after a Zombie Apocalypse. He's watched his colleagues be infected and killed, run off (and presumably die), or suicide until he was all alone. By the time the protagonists find him, the generator is nearly out of fuel and the CDC is less than a day away from self-destructing. He knows it's going to blow, but chooses to stay and end it rather than leave.
Frobisher kills his family and then himself in Torchwood (Children of Earth).

Music

Ultimate Showdown of Ultimate Destiny ends with Mr. Rogers committing seppaku.

Theater

William Shakespeare, of course, used this trope in his tragedies:
- Othello: Othello stabs himself.
- Julius Caesar: Brutus kills himself in the end, though it's unknown how many of the other conspirators were hunted down and killed off hand.
- Hamlet narrowly averts this (or maybe it subverts it); at the end Hamlet's friend Horatio is so overwhelmed by the events of the plot that he tells a dying Hamlet that he's going to kill himself; Hamlet tells him not to, he needs to be the Sole Survivor to tell Fortenbras that he (Fortenbras) is now the king of Denmark.
Played with in Penn & Teller Get Killed: the titular duo get the titular killed after a series of pranks which Penn set up to pretend that someone was out to kill him; the actor Penn hired kills himself because Penn set it up so well that nobody will believe that he didn't kill Penn & Teller. The actor's friend, a would-be politician who came to the post-performance party, kills himself because his career is over before it even began. A pair of cops show up; one takes the Vomiting Cop routine to its ultimate conclusion, killing himself, and the other one does too. Fade to Black as more and more people come across the crime scene and kill themselves. So you think that each one would be the final suicide, but it just keeps going.

Web Comics

In The Order of the Stick, Xykon uses a Symbol of Insanity to force a large crowd of paladins to fight one another to the death. When the last surviving paladin recovers from the symbol's effects, she commits Seppaku Atop a Mountain of Corpses.

Western Animation

The Simpsons once made a ripoff of Hamlet that ended with Marge (portraying Gertrude) killing herself not to clean up all the mess.
South Park uses this as a frequent gag/Deus ex Machina.

Real Life

School shootings often end with the perpetrator(s) shooting themselves. That's enough.
Inverted with the Nuremberg trial: Hermann Goering poisoned himself before the death sentences were carried out, since he would have been the first one to be hanged.
In the siege of Masada the residents of the Masada decided to kill each other because they didn't want to be taken prisoner. they killed each other instead of themselves because suicide is a grave sin in Judaism (there religion). predictably may have left one guy left who had to kill himself. It may be noted that there were far fewer skeletons found in masada then the stated number of people who killed themselves, so the mass suicide thing might just be a myth.