“I thought what the president was doing was fundamentally wrong.....'

William D. Ruckelshaus, who resigned as deputy attorney general rather than carry out President Richard M. Nixon’s illegal order to fire the independent special Watergate prosecutor in the constitutional crisis of 1973 known as the “Saturday Night Massacre,” died on Wednesday at his home in Seattle. He was 87.

His death was confirmed by his daughter Mary Ruckelshaus.

A lawyer and political troubleshooter, Mr. Ruckelshaus twice headed the United States Environmental Protection Agency, as its founding administrator from 1970 to 1973 under Nixon, and from 1983 to 1985 under President Ronald Reagan. He won praise for laying the new agency’s foundations, and later for salvaging an E.P.A. that had strayed from its mission and lost the confidence of the public and Congress.

Mr. Ruckelshaus was a champion of America’s natural resources in his home state of Indiana; in Washington State, where he lived; and while serving on presidential commissions and conservation groups. But he also worked for big business, was not an environmentalist of the Greenpeace and Sierra Club stripe, and in 50 years of public and private service was hailed and vilified by partisans on both sides as he tried to balance economic and ecological interests.

For many Americans, however, the deeds of Mr. Ruckelshaus’s varied career were all but eclipsed by his role in the events of a single night in the autumn of 1973, as the political dirty tricks and cover-up conspiracies of the Watergate scandal closed in on his boss, the beleaguered President Nixon.

The scandal had already forced some of Nixon’s closest associates to resign and face criminal charges, and Mr. Ruckelshaus, with his E.P.A. successes and reputation for integrity, was named acting head of the F.B.I. in April 1973, replacing L. Patrick Gray III, who had allowed Nixon aides to examine Watergate files and had even destroyed evidence in the case.

Mr. Ruckelshaus was soon named the top deputy to Attorney General Elliot L. Richardson. And on a night of high drama, as the nation held its breath and constitutional government appeared to hang in the balance, Nixon ordered his top three Justice Department officials, one after another, to fire the Watergate prosecutor, Archibald Cox, rather than comply with his subpoena for nine incriminating Oval Office tape recordings.

Mr. Cox’s complete independence had been guaranteed by Nixon and the attorney general during the prosecutor’s Senate confirmation hearings the previous May. He could be removed only for “cause” — some gross malfeasance in office. But none was even alleged. Nixon’s order to summarily dismiss Mr. Cox thus raised a most profound question: Was the president above the law?

Mr. Richardson and Mr. Ruckelshaus refused to fire Mr. Cox and resigned even as orders for their own dismissals were being issued by the White House. But Robert H. Bork, the United States solicitor general and the acting attorney general after the dismissal of his two superiors, carried out the presidential order, not only firing Mr. Cox but also abolishing the office of the special Watergate prosecutor.

The dismissals, all on Saturday, Oct. 20, labeled the “Saturday Night Massacre” by news media, set off a firestorm of protest across the country. Some 300,000 telegrams inundated Congress and the White House, mostly calling for Nixon’s resignation. The outcry was so ferocious that the White House said within days that it had decided to surrender the tape recordings after all.

Less than a month later, a federal judge ruled that Mr. Cox’s dismissal had been illegal and ordered him reinstated, but Mr. Cox indicated that he did not want the job back. After a protracted legal struggle, scores of tapes were eventually turned over to Mr. Cox’s successor, Leon Jaworski, and Mr. Nixon, facing certain impeachment in the House and conviction in the Senate, resigned in August 1974.

Vice President Gerald R. Ford assumed the presidency, Mr. Cox returned to teaching at Harvard, Mr. Richardson was named Mr. Ford’s commerce secretary in 1976, and Mr. Bork became a federal judge whose nomination to the Supreme Court by President Reagan in 1987 was defeated in the Senate. Mr. Ruckelshaus, who joined a Washington law firm and soon moved to Seattle, said he had no regrets.

“I thought what the president was doing was fundamentally wrong,” he told The New York Times years later. “I was convinced that Cox had only been doing what he had the authority to do; what was really of concern to the president and the White House was that he was too close. He hadn’t engaged in any extraordinary improprieties, quite the contrary.”