Why destroy Laketown's bridge?

[Rikae]

Originally Posted by davem

Smaug flies to the mountain, lands on it, & then comes down the slopes & sets the woods on fire. I take that to mean that he landed & then crawled down. The alternative, that he landed, then took off & flew down to the woods doesn't make sense - why land on the mountain-top at all - why not just fly to the woods directly?

Excellent point. Not to mention that "came down the slopes" doesn't sound the least bit like it describes flight.