NEW YORK (AP) _ The News & Observer of Raleigh, N.C., won the 1996 Pulitzer Prize for public service journalism Tuesday for stories on the environmental and health risks of waste disposal systems in the hog farming industry.

The New York Times won three Pulitzers and Newsday won two.

The prize for spot news reporting went to Robert D. McFadden of The New York Times for writing and reporting on deadline.

The staff of The Orange County (Calif.) Register won for investigative reporting for stories that uncovered fraud in a fertility clinic.

The award for explanatory journalism was won by Laurie Garrett of Newsday for her reporting from Zaire on the Ebola virus outbreak.

Another Newsday reporter, Bob Keeler, won the beat reporting prize for his detailed portrait of a progressive local Roman Catholic parish.

The national reporting prize went to Alix M. Freedman of The Wall Street Journal for her coverage of the tobacco industry, including a report that showed how ammonia additives heightened nicotine potency.

David Rohde of The Christian Science Monitor won the international reporting award for his reports on the massacre of thousands of Bosnian Muslims in Srebrenica.

The feature writing prize went to Rick Bragg of The New York Times for his stories about contemporary America, and E.R. Shipp of the New York Daily News won the commentary award for her columns on race, welfare and other social issues.

The criticism prize was awarded to Robert Campbell of The Boston Globe for his writing on architecture, and the editorial writing prize went to Robert B. Semple Jr. of The New York Times for his editorials on environmental issues. Jim Morin of The Miami Herald won the editoral cartooning Pulitzer.

The spot news photography prize was awarded to Charles Porter IV, a free-lancer, for his photographs taken after the Oklahoma City bombing showing a 1-year-old victim being handed to and being cradled by a fireman.

The photographs were distributed exclusively to newspapers by The Associated Press.

Stephanie Welsh, a free-lancer, won the feature photography prize for a sequence of photos of a female circumcision rite in Kenya. The photos were published by Newhouse News Service.

A special award was given to Herb Caen, the San Francisco Chronicle columnist, for what the Pulitzer board described as ``his extraordinary and continuing contribution as a voice and a conscience of his city.''

The prizes, the most prestigious awards given for journalism, are presented annually by Columbia University. Prizes include an award of $3,000, except for the public service award, which is a gold medal.