What was going on when I was born?

Andre Kertesz celebrated his 90 birthday this month, and he did not celebrate alone. In addition to a surprise party on a Fifth Avenue rooftop with photography's elite in attendance, a book was published to honor the artist that interweaves written tributes to his achievements with reproductions of many of his most wonderful photographs. Published in England, which in the last four years has very nearly made Mr. Kertesz an honorary citizen, the book contains contributions by his British and American friends. These include Weston Naef, new curator of photography at the Getty Museum in Malibu, Calif,; Charles Harbutt, one of the master's younger compatriots, and Harold Riley, the English artist who edited and designed the book.

Now, when days are hot and nights are soft, is the season that draws New Yorkers to water's edge. Not for more than a century perhaps have weekend strollers been able to stretch their legs and imaginations on more shoreline, along waterfronts that were once cut off by the barrier of piers and warehouses that symbolized the city's commerce. And yet, a fascination with the water has always stirred the restless mind in New York, sometimes tranquilizing it, sometimes spurring it to new adventure. Herman Melville caught the flavor in a passage in ''Moby-Dick,'' when he urged the reader to ''circumambulate the city on a dreamy Sabbath afternoon.'' Melville, who often went to New York's waterside, found thousands there fixed in reveries. ''Nothing,'' he wrote, ''will content them but the extremest limit of land.''

Companies David H. Murdock sold his 5 percent interest in Occidental Petroleum back to the company at more than $12 a share above the current market price and resigned from the board. Sources close to the situation attributed the move to conflicts between the Los Angeles businessman and Armand Hammer, Occidental's 80-year-old chairman. (Page D1.) The F.D.I.C. is quickly assembling management, legal and financial teams to assist in the takeover of Continental Illinois. Morgan Stanley has been hired, and reportedly also the New York law firm of Cleary, Gottlieb, Steen & Hamilton. Meanwhile, the names of several prominent bankers have surfaced as possible heads for the new Continental. (D1.)

Later this summer divers hope to begin unlocking the secrets of the Sindia, a four-masted ship that sank near shore here in 1901. The salvage crew - headed by two commercial divers, Edward R. Michaud and Michael Kenney - says the 329-foot Sindia is loaded with valuable contraband not listed on the ship's manifest. Mr. Michaud said today that the ship, returning to New York from Japan when she went aground, had been carrying cargo that might be worth $10 million to $30 million. The salvagers cleared a legal hurdle this week by offering a share in anything they found to beachfront property owners near the wreck who claim ownership of the Sindia.

Technicians and nurses in critical- care units at several New York City hospitals stopped working yesterday as the pressure increased for a settlement in the strike at hospitals and nursing homes. Technicians withdrew from several kidney dialysis centers and nurses stopped working at a Brooklyn hospital's operating rooms and intensive- care unit. The strike against most of the city's private, nonprofit hospitals, which enters its eighth day today, showed no sign of a settlement, with both sides far apart. The striking union, District 1199 of the Retail, Wholesale and Department Store Union, A.F.L.-C.I.O., had agreed to keep its members working in critical, life-sustaining jobs and to send in nurses or technicians in emergencies.

President Reagan today belittled Nicaragua's plans for elections this fall and declared that the United States had a ''moral responsibility'' to aid anti-Government insurgents as long as Managua promoted ''Communist interference'' in the region. Speaking to leaders of 13 Caribbean governments at a conference at the University of South Carolina, Mr. Reagan said Nicaragua planned elections in November only after ''mounting internal pressures and disillusionment abroad'' over its policies. ''We would wholeheartedly welcome a genuine democratic election in Nicaragua,'' the President told the leaders at a luncheon at a campus student center. ''But no person committed to democracy will be taken in by a Soviet- style sham election.''

The board of the Michigan National Corporation said yesterday that it had requested and received the resignation of Stanford C. Stoddard, chairman and chief executive of the bank holding company. The board, which made the request at its regularly scheduled meeting Wednesday evening, did not explain its action. Mr. Stoddard, 53 years old, had no comment. He is the son of the founder of the company's lead bank and owns 6.5 percent of the company's common stock. He had taken an indefinite leave of absence on July 12.

An obituary in some editions on June 29, of the Israeli military hero and archeologist Yigael Yadin, inaccurately characterized accounts of events at Masada in A.D. 73 that were confirmed by his excavations there.

Because of an editing error, a front- page subheading and a dispatch from San Francisco in some copies yesterday incorrectly described the Democratic Convention appearances by Walter F. Mondale, Senator Gary Hart and the Rev. Jesse Jackson after the balloting. The three men addressed the delegates separately.

''And when we - and when we in this hall speak for America, it is America that is speaking.

The first inkling Wanda Hasely had that her quiet, unemotional neighbor sometimes turned violent was about a week ago when his 13-year-old daughter came to her apartment with welts on her face and said ''her daddy had slapped her around.'' Today, the day after the neighbor, James Oliver Huberty, opened fire in a McDonald's restaurant, killing 21 people and wounding 19 before being slain himself, Mrs. Hasely and others who were acquainted with him - no neighbors or co-workers seem to have known him well - painted the picture of a hotheaded loner who had accumulated an arsenal of weapons. In the days before and hours after the rampage, Mrs. Hasely said, she learned that Mr. Huberty was an obsessive man who had already developed his 13-year-old girl, Zelia, into a black- belt karate fighter, and slept, according to Mrs. Hasely's daughter, with a gun under his pillow. Bitterness Remembered The police said today that there was ''no known motive'' for the massacre. but that the 41-year-old gunman had ''seemed somewhat despondent over the loss of his job.'' Today, Mr. Huberty was quoted by his wife, Etna, as saying ''I'm going to hunt humans'' as he left their apartment Wednesday. In a television interview, Mrs. Huberty said her husband was calm at the time and she did not know what his words meant.

The address by Mondale, page A12; the Ferraro speech, page A14. SAN FRANCISCO, July 19 - The Democratic National Convention nominated Representative Geraldine A. Ferraro of Queens for Vice President by acclamation today. The New York delegation made the formal motion that forged a historic ticket that the Presidential nominee, Walter F. Mondale, called ''a new door to the future.'' In his speech accepting the nomination for President, Mr. Mondale pledged fair policies and a cut in the deficit. And he sounded the rallying cry for his party and described the theme of the Democrats' case against President Reagan, terming Mr. Reagan's policies a threat to the nation's long- term economic security and the physical survival of its families.