Denis Goldberg, 87, a railway engineer who became one of the most prominent white anti-apartheid activists in South Africa, spending 22 years behind bars for plotting to overthrow the country’s brutal system of racial oppression, died April 29 at his home in Hout Bay, near Cape Town.

Working alongside Nelson Mandela and other leaders of the African National Congress, Mr. Goldberg was part of a multiracial coalition dedicated to overthrowing apartheid, the segregated system that propped up white minority rule in South Africa for nearly half a century. He went on to become a kind of elder statesman for the movement, calling on the ANC — modern South Africa’s ruling party — to recommit itself to social justice and economic equality amid a wave of recent corruption allegations.

Irrfan Khan, 53, veteran character actor in Bollywood movies and one of India’s best-known exports to Hollywood, died Wednesday at a Mumbai hospital. He was admitted with a colon infection last week. He played the police inspector in “Slumdog Millionaire” and the park executive Masrani in “Jurassic World.” He also appeared in “The Amazing Spider-Man,” the adventure fantasy “Life of Pi,” and the drama “The Namesake.” Mr. Khan made his screen debut in the Academy Award-nominated 1988 drama “Salaam Bombay!,” a tale of Mumbai’s street children. He worked with directors Mira Nair, Wes Anderson and Ang Lee. In 2018, he was diagnosed with a rare neuroendocrine cancer and underwent months of treatment in the United Kingdom. “I trust, I have surrendered,” he wrote in a note after he broke the news of his battle with cancer.

Lynn Harrell, 76, a prizewinning American cellist and teacher, renowned for the mixture of technical command and sweet songfulness of his playing over a career that spanned six decades, died Monday at his home in Santa Monica, California. The cause of death was not available.

“The big bear of the cello is gone,” conductor Leonard Slatkin, a longtime friend, said in a statement. “Was there ever a more congenial musician? It was never work with Lynn, that smile always letting you know that he was at one with the music and eager to collaborate with you, wherever the turn of phrase went.”

Eavan Boland, 75, who expanded the voice of Irish poetry by consciously writing from a female point of view, putting the lives and experiences of women at the center of her poems, died Monday at her home in Dublin. Stanford University, where she was director of the creative writing program, announced the death. The cause was a stroke.

Nick Kotz, 87, who won a Pulitzer Prize in 1968 for exposing unsafe and unsanitary conditions in the nation’s meatpacking plants and who later became a Washington Post reporter and the author of books investigating hunger, civil rights and military contracting, died April 26 at his home near Broad Run, Virginia. According to a statement from the Virginia State Police, Mr. Kotz stopped his car in his driveway to retrieve an item from the back seat. The car rolled backward, striking him. He died at the scene.

Jack Randall, 95, a distinguished ichthyologist and coral specialist who discovered and named more species of fish than anyone in history, died April 26 in his home in Kaneohe, Hawaii. The cause was complications from cancer.

Dr. Randall spent much of his career classifying organisms, engaging in the laborious and tedious branch of science known as taxonomy. By the time of his death, he had described and named more than 830 species fish. That number will rise in the coming years as his colleagues finalize numerous papers still in the works. His well-earned nicknames were “Dr. Fish” or “the Fish Man.”

Donald Kennedy, 88, a neurobiologist who steered Stanford University to rising national influence as its president through the 1980s but stepped down amid intense scrutiny of how the Silicon Valley research powerhouse charged the government for overhead expenses, died April 21 in Redwood City, California. Kennedy had a stroke in 2015, but the immediate cause was complications from COVID-19.

A champion of science and public service, Dr. Kennedy was commissioner of the Food and Drug Administration during the Carter administration before he began his 12-year run as Stanford’s eighth president in 1980. After his presidency, he was editor in chief of Science magazine for eight years and wrote editorials urging policymakers to focus on challenges such as climate change.

Ronan O’Rahilly, 79, the rebellious entrepreneur whom The Times of London called “the godfather of the pirate radios which revolutionized British in the 1960s,” died April 20, in his native Ireland. He drew an audience of 25 million in his prime and was credited with helping spark the Swinging Sixties and forcing the BBC to “get with it” by popping its own pop music channels.

Philip Kahn, 100, decorated World War II veteran, died April 17 of the coronavirus at home in Westbury, New York. He believed that history repeats itself, a truism that hit home for his family in extraordinary fashion. His twin brother, Samuel, died as an infant during the Spanish flu pandemic of 1918-19. “He was a very healthy 100,” Warren Zysman, one of Kahn’s grandsons, said. “He watched the news, he was completely aware of the pandemic. When he started coughing, he knew he might have it, and he knew the irony of what was going on.”

Avraham Rabby, 77, a blind activist and management consultant who passed five State Department entrance examinations and in 1989 prevailed in a protracted dispute with the department over his qualifications to be a Foreign Service officer, died April 17 in a hospital near Tel Aviv. The cause was cancer. In 1990, Mr. Rabby began a 17-year Foreign Service career that would include posts in Europe, Africa, South America and South Asia. He was a “champion for the employment of the disabled at the State Department,” said Judith E. Heumann, special adviser for disability rights at the State Department during the administration of President Barack Obama.