Lord Capulet describes his daughter's death as a kind of awful mistake wherein Romeo's dagger has become somehow sheathed, by its own volition, in her bosom rather than in his scabbard. Capulet says to Lady Capulet,

O heavens! O wife, look how our daughter bleeds!
This dagger hath mista'en, for, lo, his house
Is empty on the back of Montague,
And it mis-sheathed in my daughter's bosom (5.3.210–213).

When Juliet wakes up in her tomb, finding the body of her husband, Romeo, killed by poison, she first hopes that there is yet some poison remaining in the vial that she can drink to join him in death. She has refused to leave the tomb with Friar Lawrence and chooses instead to use Romeo's dagger to take her life rather than to live without her love.

Thus, when she is found, she has Romeo's dagger thrust into her breast. Capulet's description personifies the dagger, referring to it as a male and describing Romeo's empty scabbard as the dagger's "house." It is as though he does not want to accept the fact that his daughter would rather take her own life than endure the life he has given her, and so he describes the dagger as being somehow responsible for her fate rather than her own hand.

What does Lady Capulet say about Romeo and Juliet's death?

The dead bodies of Romeo and Juliet lie together in the Capulet family tomb. As one can imagine, everyone is shocked and saddened by the tragic demise of these two young lovers, cruelly snatched from the world much too soon.

Lady Capulet, Juliet's mother, is especially hard-hit by the terrible sight of Romeo's and Juliet's dead bodies. As soon as she casts eyes upon them, she is plunged into unimaginable grief:

O me! This sight of death is as a bell,

That warns my old age to a sepulcher.

(act 5, scene 3, lines 221–222)

In other words, the death of Romeo and Juliet is like the ominous tolling of a bell that reminds Lady Capulet that she is old and will soon die herself.

In Shakespeare's day, and for many years after, it was quite common for a bell to be tolled when someone was about to die, when they actually died, and when they were buried. The tragic death of Lady Capulet's daughter and her beloved Romeo seems to her like a passing bell, which was rung to warn someone of impending death.

Though Lady Capulet exaggerates somewhat, allowances must be made for her grief-stricken state of mind. Under the circumstances, it's perfectly understandable that she should feel that her life is almost at an end. Lady Capulet is so utterly devastated by these heartbreaking deaths that she's convinced that she will soon be joining Romeo and Juliet in death.