Well, this poor birch bark dropped down and lies asunder, despite having been joined together to the tree, Robert Frost. I think the weight of life was just a bit too much to bear.

....Earth’s the right place for love:
I don’t know where it's likely to go better.
I'd like to go by climbing a birch tree,
And climb black branches up a snow-white trunk
Toward heaven, till the tree could bear no more,
But dipped its top and set me down again.
That would be good both going and coming back.
One could do worse than be a swinger of birches.

Or, maybe, it suffered from the suppressed anger that not only leads to the destruction of one, but to the moral corruption of the other.

A POISON TREE
By William Blake

I was angry with my friend;
I told my wrath, my wrath did end.
I was angry with my foe:
I told it not, my wrath did grow.
And I waterd it in fears,
Night & morning with my tears:
And I sunned it with smiles,
And with soft deceitful wiles.
And it grew both day and night.
Till it bore an apple bright.
And my foe beheld it shine,
And he knew that it was mine.
And into my garden stole,
When the night had veild the pole;
In the morning glad I see;
My foe outstretched beneath the tree.