Why?

I have a heavy heart.
I just received an email from my dear friend Aimee.
Aimee lost her daughter, Sophie, last winter. The situation was beyond complicated. Sophie, who was the living twin in a pregnancy in which one twin was a molar pregnancy, died as the result of complications when Aimee's hormone levels became toxic and her organ systems began to shut down. Nobody had realized there was a molar pregnancy in there with Sophie as this is practically a medically undocumented situation. Aimee began to bleed out, and Sophie died.
Aimee almost died, too.
And everyone said, You are so lucky to be alive!
Nobody worried too, too much about Sophie, because Aimee was SO lucky to be alive.
That's what they said to her, anyway.
But Aimee worried quite a bit about Sophie, her third daughter who had died at 37 weeks gestation, who she never saw or held because she was in a coma.
Of course, Aimee's heart is broken. Quite.
With joy, Aimee announced to me a month ago that she was again pregnant. We were so happy together.
Today I read this on my email

The baby died.
I have a D & C tomorrow.
I can't write right now.

Oh, oh, oh.

I can't write right now either.

Why do such sad things happen to such good people?