Kurt Vonnegut, an American cultural hero celebrated for his wry, loonily imaginative commentary on war, apocalypse, technology, materialism and other afflictions in "Slaughterhouse-Five" and other novels, has died. He was 84.

One of the last of a generation of great American novelists of World War II, Vonnegut died Wednesday night in New York City.

Vonnegut suffered brain injuries in a fall several weeks ago, said his wife, photographer Jill Krementz.

Unorthodox in structure and patently antiwar, the novel [Slaughterhouse-Five]resonated with a rebellious younger generation. Vonnegut became an icon of the countercultural 1970s and his book became a milestone of postmodern American literature, unequaled in force or artistry by any of his later novels.

The plan, confirmed yesterday by the California biotechnology company leading the effort, calls for large-scale cultivation in Kansas of rice that produces human immune system proteins in its seeds. The proteins are to be extracted for use as an anti-diarrhea medicine and might be added to health foods such as yogurt and granola bars.

But critics are assailing the effort, saying gene-altered plants inevitably migrate out of their home plots. In this case, they said, that could result in pharmacologically active proteins showing up in the food of unsuspecting consumers.