Romeo and Juliet#2

What story does Friar John tell Friar Laurence as explanation as to why he could not deliver the letter to Romeo? He says that he could not deliver the letter because the people in that town thought he had the plague and it would infect others.
Why is Paris at the tomb? What happens to him? He wants to lay flowers on Juliet’s body. He is killed by Romeo.
How does Romeo die? He drinks poison.
Why does Friar Laurence run out when he sees Romeo dead? He is afraid that he will get arrested for the murder.