When the marriage ceremony was over he should have gone straight to the prince and told him, and keep the rest from happening, but he kept with Romeo and Juliet’s wishes and kept the secret. The “sleeping draught” that he gave to Juliet. He should have told the families then, before he gave it to her even if he thought he had it all figured out, because being a father of the church he probably knew both Montagues and Capulets, so he would be committing a moral sin to both the families. The same goes for the nurse, she had her doubts after Romeo killed Tybalt saying that shame should come to Romeo because he is an awful man to kill Tybalt, but soon changed her mind after Juliet scolded her. The thing is, if you look at it hard enough the deaths of both Tybalt and Mercutio are Mercutio’s fault. Because if you remember in act three, scene one, Benvolio is trying to get to a safe place because he is afraid of a fight with the Capulets’. But Mercutio stays out and when Tybalt comes looking for Romeo, Mercutio try’s to pick a fight with him when it is obvious that Tybalt wants nothing to do with Mercutio. When Romeo turns up and doesn’t accept the offer to fight Mercutio takes it on him to act and fight. Therefore I believe that Mercutio set into motion the events that would lead to the deaths of Romeo and Juliet.
Yet there is still one thing that remains to be the final school of thought. That it was all due to fate. The Prologue points out that Romeo and Juliet have fate against them. It says that their love is "death-marked," and they have no control over what happens. It is their misfortune that leads to the sorrowful and tragic ending of the play. Then Peter runs into Romeo and Benvolio on the street. It is this encounter that enables Romeo to read the list of names of guests for the Capulet feast. Had Romeo not run into Peter, he would have never gone to the feast, and hence, never even met Juliet. It is fate that makes this encounter possible. But before Romeo enters the house of the Capulets, he speaks about an unknown danger "hanging in the stars." This notion of events expected to occur being written in the stars explains how life is predetermined by fate. Romeo senses that something bad may occur based on his fate. After the ball, Romeo goes and tells the friar about Juliet, and the friar warns Romeo that people who act impulsively often have very negative and destructive consequences. This warning reminds the audience that Romeo's fate is already predetermined, and that there will, in fact, be negative consequences to his actions. Then while Mercutio died he yells out “A plague on both your houses”. These words are a reminder to the tragedy that is fated to occur. Romeo and Juliet have very little to do with what happens to them at the end of the play. It is sheer misfortune and fate that lead to the tragic ending. And again in act three, scene five, Juliet tells Romeo of her vision of him dead at the bottom of a tomb. This is foreshadowing to the already destined event these two lovers will soon face – death. Later when Romeo learns that Juliet is dead. He says that he defies fate, by saying that he defies what is written in the stars. He refuses to accept that Juliet is dead. What Romeo does not realize is that he has no control over his destiny. No matter how angry or motivated he is to change what is written in the stars, he cannot. It is already predetermined. When Friar John explains to Friar Laurence that he never made it to Mantua to give the letter to Romeo it had to have been fate that stopped him from going. Because Romeo never receives this letter, he buys poison with the intention to kill himself upon seeing her dead in her tomb. It is fate that did not allow the friar to reach Romeo in Mantua. And thus, it is also fate that Romeo buys the poison and eventually kills himself by Juliet's side. Juliet wakes up from the sleeping potion and asks the friar where Romeo is. The friar responds by saying that some higher power has changed their original plans. This higher power is what people have no control over - fate. Through fate, the friar does not make it to Juliet's tomb on time. Romeo kills himself before the friar can tell him that Juliet is not really dead. This is not the friar's fault. Rather, it is fate that he did not get there on time.
With this in mind I have concluded that was not the fault of Romeo and Juliet. Nor was it the fault of any one character. The only other factor that could have caused their deaths would be fate. Therefore I conclude that it was by the powers of fate that Romeo and Juliet died, and that they had no choice in their demise.