The hobbit chapter 14 question " Fire and Water"

There was very little effort put into rebuilding Lake Town.

Shelters could be contrived for few (the Master had one) and there was little food (even the Master went short). Many took ill of wet and cold and sorrow that night, and afterwards died, who had escaped uninjured from the ruin of the town; and in the days that followed there was much sickness and great hunger.

Until the Elven King answered Bard's call....

Their plans were soon made. With the women and the children, the old and the unfit, the Master remained behind; and with him were some men of crafts and many skilled elves; and they busied themselves felling trees, and collecting the timber sent down from the Forest. Then they set about raising many huts by the shore against the oncoming winter; and also under the Master's direction they began the planning of a new town, designed more fair and large even than before, but not in the same place.