The lobsters have died, and all at once Long Island has lost an industry, a trademark and a way of life.

Long before the ducklings and the potatoes and the grand estates along the north shore gave Long Island an identity, it was the lobsters in the Long Island Sound that built up many of the harbor villages, fed people, brought settlers. A 350-year industry may be crippled permanently, and we may never know why. But the lesson is deep and profound.

There probably isn't one single reason why Long Island Sound lobsters have suddenly become susceptible to ancient Western Sound microbes to which they used to be invulnerable. Like the high breast cancer rates in parts of Long Island, there is probably a hard-to-identify combination of factors at work. Runoff of chemicals after last year's Hurricane Floyd. Overflow of raw sewage from inadequate treatment plants in the Western Sound. Aerial spraying to fight the West Nile Virus that hit or ran into the water (the lobster is an arthropod, and susceptible to pesticides). Any of them, all of them. Take your pick. We might never know the whole truth.

But 90 percent of the Long Island Sound lobsters seem to have died between last fall and this year, crippling our local lobstering industry. Lobsters from Maine and Massachusetts have taken up the slack. Our $30 million a year industry is probably past life support.

Well-equipped lobster boats cost about $200,000 to start and many lobstermen spend their lives paying off loans. One really bad year like this, and most of them are just out of business, getting what they can for their equipment and moving on to other careers, other lives. Lobsters are only harvested about four times a year in the Sound, a total of maybe a month of serious trapping. But once the pros are out of the business, the generational chain is broken and the lobsterman of the future won't be from Long Island.

There will probably always be a few lobsters in the Sound, and perhaps the species will make a comeback over the years. Little Neck Bay and Manhasset Bay used to be teeming with clams and oysters that were a huge part of the local economy. Some clams are still there, you just can't safely eat them.

Long Island survived. People bought homes, drove their cars, went to work, raised their families and sprayed their lawns. It was just one more old thing about Long Island that wasn't there anymore.

The warnings were there for years. We've known about the treatment plants, the overflow, the runoff, all of it. We can't yet point to the specific bullet that killed the lobsters, but we all played a roll in firing the gun.

A gun that could be pointed at us, too.