NEW YORK - Sidney Zion, a journalist whose family tragedy helped lead to changes in how many hours medical residents work, has died. He was 75.

Zion, who had written for The New York Times, the Daily News and the New York Post, died Sunday at Calvary Hospital in Brooklyn. He had been suffering from bladder cancer , said his son, Adam Zion.

In March 1984, Zion took his 18-year-old daughter, Libby, to New York Hospital because she was agitated and suffering from high fever. She died the next morning of cardiopulmonary collapse.

Zion blamed doctors for her death, saying they had given her a painkiller that can react badly with an antidepressant she told doctors she was taking. He also charged that the hospital systematically overworked and undersupervised its young doctors-in-training.

Sidney Zion and his wife sued the hospital and the doctors in 1985. A jury returned a split verdict 10 years later, deciding that the hospital, its resident doctors and Libby herself were all partly to blame for her death.

In 1989, New York became the first state to regulate intern and resident hours. They were limited to 24-hour shifts, not the 36-hour ones that were common. The average work week was capped at 80 hours instead of the usual 100. More supervision by senior physicians was also required. Nationwide regulations came in 2003.