In Julius Caesar, Act IV, according to Brutus, what were the reasons for Portia's death and how does he respond to her death?

This event occurs in Act IV scene 3 of this great tragedy.
Brutus gives a typical stoical response, in contrast to Cassius, when he tells him that
he has received news of his wife's death. According to him, Portia killed herself
because she was missing Brutus so much and also she had heard news that the opposition
against him was now so strong, she became distraught and "swallowed fire" when her
servants were not at home. According to Plutarch, she killed herself by putting hot
coals in her mouth.

However, what is interesting is the way
that Brutus chooses to supress all emotion and carry on with the job at hand. Note what
he says:

Speak
no more of her. Give me a bowl of wine.

In this I bury all
unkindness, Cassius.

In a
short sentence he dismisses her as if she never existed and goes on to make peace
between himself and Cassius. This of course is questionable, but a lot depends on the
individual director as to how they would stage this scene. Some would have Brutus
showing some form of emotion, at least in private, or perhaps barely being able to
master himself. It depends a lot on how sympathetic you want the audience to feel for
Brutus at this stage of the play.