Why destroy Laketown's bridge?

[Rikae]

Originally Posted by Macalaure

Apart from the problems already mentioned, note that in the text Tolkien talks of bridges, while this Laketown only possesses one. The prof probably didn't have pedantic accuracy in mind when he drew this.

Indeed (that's my point in babbling about "10 feet above ground level" etc.)
I love Tolkien's illustrations - their style and feel is delightful - but this wouldn't be the first time one seemed to make something in the text impossible (I can't remember which, but I know I've looked at one of his drawings before and thought "but that's not accurate! It's not like that in the book!")