At a time when investigative journalism is increasingly under fire, Pulitzer Prizes were awarded yesterday to two newspapers -- The Philadelphia Inquirer and the Fort Worth Star-Telegram -- that have been under siege in their communities over the very stories that won the awards.

Mark J. Thompson of the Fort Worth Star-Telegram won the prize for public service for a series of stories on a design problem in Bell helicopters that has led to the deaths of nearly 250 U.S. servicemen since 1965.

The series, which ran in March 1984 and led to the grounding of nearly 500 helicopters, drew a storm of protest in Fort Worth, where Bell Helicopters International is the second largest employer. The stories also resulted in more than 1,200 cancellations of subscriptions for the paper, demands by the company for a retraction and a banning of the paper on Bell company premises.

Similarly, The Philadelphia Inquirer won for its articles on attacks by police dogs on more than 300 citizens. The stories led to a change in the training and use of K-9 units. Last weekend, the paper learned it may be sued for libel by seven police officers, executive editor Gene Roberts said.

"We view this as harassment, pure and simple, and intend to countersue," Roberts said yesterday.

While several of the major journalism awards focused on local news, three Pulitzers for the arts had European themes.

"Foreign Affairs" by Alison Lurie, a novel based on two professors on a continental sabbatical, won the prize for fiction.

"Sunday in the Park with George," with music by Stephen Sondheim and based on the book by James Lapine, won the prize for drama, becoming the first musical to win since "A Chorus Line" in 1976. The show was inspired by the work and life of French pointillist Georges Seurat, and has already won a Grammy award and prizes from the New York Drama Critics and the Drama Desk. The stage manager announced the latest honor to the audience and cast at yesterday's matinee. When the cast left the stage, Sondheim and Lapine were waiting backstage to celebrate with them.

And finally, Stephen Albert, a 44-year-old composer who lives in Massachusetts, won for "Symphony RiverRun," a work based on James Joyce's novel "Finnegans Wake." The work was commissioned in 1983 by the National Symphony Orchestra and premiered at the Kennedy Center in January.

The Pulitzer board, which met last week to determine those who would receive the award and the $1,000 prize money, also picked Murray Kempton, columnist for Newsday, for commentary. Kempton, an almost legendary figure in New York, where his highly personal columns often deal with city problems, said he was "touched" that the prize went to "somebody who does almost exclusively local stuff.

"There wasn't a single piece analyzing the struggle over Nicaragua in the Congress, and I'm tremendously proud of that," said Kempton, who also writes biting and witty analyses that have been known to stray into national and international issues.

For nonfiction, the board picked longtime journalist, writer and raconteur Studs Terkel for his book "The Good War: An Oral History of World War II."

Terkel, 72, from Chicago, who has often found himself at odds with presidents and Chicago mayors over the years, said: "Now, I'm respectable, and I must say I find this very amusing. Now that I've been allowed this aura of respectability, I can say things that are even more outrageous."

In picking winners of the prestigious awards this year, the Pulitzer board passed over three newspapers that have been traditional winners -- The Washington Post, The New York Times and The Wall Street Journal.

Three prizes went to journalists close to the D.C. area.

Thomas Turcol, 31, of The Virginian-Pilot and Ledger-Star of Norfolk, took the general news reporting prize for city hall coverage, which exposed allegedly false expense account claims by a local economic development official in the town of Chesapeake.

Said the paper's managing editor James Raper of Turcol, "He's just one good city hall investigative reporter."

A new prize for explanatory reporting went to Jon Franklin of The Baltimore Evening Sun, whose seven-part series called "The Mind Fixers" detailed advances in brain chemistry research. Franklin, who has been at The Evening Sun for 15 years, earlier won a Pultizer for feature writing for a story on brain surgery.

Alice Steinbach of The Baltimore Sun won the prize in feature writing for an account of Calvin Stanley, a 10-year-old blind boy who is one of the few blind individuals enrolled in the Baltimore public school system.

Other journalists who won prizes this year included Randall Savage and Jackie Crosby of The Macon (Ga.) Telegraph and News for the examination of academics and athletics at two Georgia universities. They won in the reporting on specialized subjects category, another new prize.

The Des Moines Register's Thomas Knudson won the national affairs award for a series on the dangers of farming. Howard Rosenberg of The Los Angeles Times won for his television criticism, and Jeff MacNelly of the Chicago Tribune received the prize for his editorial cartoons.

Richard Aregood of the Philadelphia Daily News won for his editorials. The St. Petersburg Times, which shared the investigative prize with The Philadelphia Inquirer, won for its reporting on alleged corruption in the office of the Pasco County sheriff.

The Inquirer's Larry Price shared the feature photography prize with Boston Globe photographer Stan Grossfeld, who also won a Pulitzer last year for The Globe.

Spot news photography went to the staff of The Register in Santa Ana, Calif. for their photos of the Olympics -- especially the Zola Budd-Mary Decker race that resulted in Decker's tumble onto the sidelines.

Newsday won the prize for international reporting on its series of articles about the plight of the hungry in Africa, making two prizes this year for the Long Island publication.

The prize for history went to Thomas McCraw's "Prophets of Regulation," which traces the history of regulation through the profiles of four men -- Charles Francis Adams, Louis D. Brandeis, James M. Landis and Alfred E. Kahn. McCraw is a professor at Harvard Business School.

The biography prize went to Kenneth Silverman for his book, "The Life and Times of Cotton Mather."

The board this year also issued a special music citation to William Schuman for "more than half a century of contribution to American music as composer and educational leader."

The poetry prize went to Carolyn Kizer's "Yin," which refers to the feminine principle and is a book mostly written as a tribute to her mother.