Why destroy Laketown's bridge?

[Sauron the White]

from skip spence

Sauron the White
I give up. You really are a peace of work, aren't you?

If you are going to try to insult me it might be nice to get the phrase right. Its not peace of work --- its piece of work. I do not remember insulting you. I am merely trying to discuss points you raise in your posts.

from Rikae

So now they only cut some of the bridges? Why?

I would guess that they can only cut which can be cut. Some bridges - the suspension types with ropes - would lend themselves to that procedure. Others - like the main Laketown bridge drawn by JRRT himself - would not lend itself to being cut.