MUMBAI, India — An Indian nurse died on Monday more than four decades after she was strangled with a metal chain, sexually assaulted and left in a permanent vegetative state. Her case had set off a national debate on euthanasia, often called “mercy killing” in India, and helped lead to the legalization of life-support withdrawal.

The nurse, Aruna Shanbaug, 66, died of pneumonia after contracting it last week, said Avinash Supe, the dean of King Edward Memorial Hospital in Mumbai, where Ms. Shanbaug had worked before spending 38 of the last 42 years in a coma there. She had been kept alive with a feeding tube.

Ms. Shanbaug was a newly engaged 25-year-old nurse when, at the end of the workday on Nov. 27, 1973, she went down to the hospital basement, where there was a “dog lab” in which animal experiments took place. A young orderly at the lab, who had waited there for her, strangled her with a dog chain, sodomized her and then fled.

The orderly, Sohanlal Bharta Walmiki, was sentenced to seven years in prison for robbery and attempted murder. Rape was not included in the charges against him because Indian law at the time did not include sodomy as a form of rape, and because the hospital had withheld the nature of the assault during the investigation.