hatland

Try not to Google the answer to this one (it's much easier than the previous puzzle):

Welcome to Hatland (population 1,000), an island country where there are only a few laws. They are:

(1) Everyone wears either a black or a white hat.
(2) No one can talk about the colors of their hats.
(3) No one can see the color of his or her hat. There are no reflective surfaces in the land.
(4) Each person who discovers he or she is wearing a white hat must go to the town square the next day and commit suicide.

(4) is pretty gruesome, but because of (2) and (3), there have never been any mandatory suicides on the island. However, one day, a shipwrecked sailor crawls to shore, and before dying, he gasps these last words: "At least one of you is wearing a white hat!"

What happens?