Ten-year-old Eve Kugler was not supposed to be on the ship that spirited her away from Nazi Europe and docked in New York City late in the summer of 1941. At the last moment, she and her older sister, both German-born Jews, received visas originally intended for two children who had fallen ill and could not travel.

That turn of fate — and her parents’ agonizing decision to accept the visas and send their daughters to America alone — assured Ms. Kugler’s survival during the Holocaust.

She and her sister would spend years in foster care thousands of miles from home, unsure whether their parents and younger sister were alive or dead and fearing the worst. But safely in the United States, they would not be among the 6 million Jews, including as many as 1.5 million Jewish children, killed by the Nazis and their collaborators.

Throughout her life, Ms. Kugler said, “the guilt I felt for securing a place of safety at the expense of a sick child never left me.”

Ms. Kugler, 94, died April 23 at a hospital in London. The cause was cancer, said her son, Mark Rosenzweig.

First in the United States, and later in her adopted home of England, Ms. Kugler became a devoted memory-keeper for the victims of the Holocaust, speaking indefatigably to schoolchildren, traveling with students and others to Nazi concentration camps, and offering herself as a living witness to the dangers of ethnic, religious and racial hatred.

“Her story is both exceptional and symbolic of a larger movement of children who survived the Holocaust and who have sought to bear witness,” said Laura Hobson Faure, the chair of modern Jewish history at Université Paris 1 and the author of the recently published book “Who Will Rescue Us? The Story of the Jewish Children Who Fled to France and America During the Holocaust.”

Ms. Kugler was born Eva Kanner in Halle, Germany, northwest of Leipzig, on Jan. 12, 1931. Her sister Ruth was a little more than a year older. Their father ran a general store, while their mother managed the home.

Life for her family and for Jews across Germany deteriorated severely after Hitler became chancellor in 1933. In 1936, Ms. Kugler’s mother was forced to deliver the third of her three daughters, Lea, at home because Jews were no longer allowed to give birth in the city hospital, Ms. Kugler told an interviewer, Bea Lewkowicz, for the Refugee Voices Archive of the Association of Jewish Refugees.

Ms. Kugler’s father applied to immigrate to what was then the British mandate of Palestine but never received permission to enter the territory.

In late October 1938, Nazi police officers arrived at the family store in search of Ms. Kugler’s grandfather. They arrested and expelled him, along with roughly 17,000 other Jews of Polish citizenship, in the first mass deportation of Jews from the German Reich. Also taken away were more than a dozen other members of her family, Ms. Kugler told the Holocaust Memorial Day Trust in Britain.

Days later, in November 1938, came Kristallnacht, or the Night of Broken Glass, a wave of antisemitic pogroms in which rioters attacked Jewish homes, businesses and places of worship across Germany. The synagogue in Halle, which had been established with help from Ms. Kugler’s grandfather, was set ablaze.

In the course of the violence, Nazis descended on her family’s home.

“I stood at my bedroom door and watched as they stormed through our apartment,” Ms. Kugler recounted. “They overturned furniture, emptied linen, clothes and kitchen cupboards, trampling on the contents. In a frenzied attack in Grandfather’s room, they tore apart his sacred Hebrew texts and desecrated his holy Sefer Torah. In the morning, Nazis ordered Mother to sweep up shards of glass from our shattered store windows that littered the pavement.”

Ms. Kugler’s father was among approximately 30,000 Jewish males arrested during Kristallnacht and taken to concentration camps. Confronting the police about her husband’s whereabouts, her mother learned that he had been taken to Buchenwald.

At that point in the Holocaust, the Nazis allowed Jews to leave Germany. “If you can get him a visa,” an official told Ms. Kugler’s mother, “then he can come out.” Returning with a fraudulent visa as well as a bribe, she arranged for him to flee to Paris and the following year joined him there with their three daughters.

Any semblance of safety was short-lived. After World War II broke out in September 1939, Ms. Kugler’s father was arrested in France because of his German nationality. With no means of supporting her daughters, her mother entrusted Ms. Kugler and her sisters to the Children’s Aid Society — the Oeuvre de Secours aux Enfants, abbreviated OSE — which placed them in a series of children’s homes while employing her as a cook.

Ms. Kugler endured terrifying bombings after Germany invaded France in May 1940. Shortly after Paris fell to the Nazis that June, France was divided into occupied and unoccupied zones.

In 1941, the U.S. government granted permission for a group of refugee children to enter the country.

The United States Committee for the Care of European Children, working with the American Friends Service Committee, a Quaker aid group, began arranging transports with the help of OSE.

In all, about 320 refugee children were evacuated from France in 1941 and 1942 via Spain and Portugal to the United States, said Hobson Faure. Ms. Kugler and her sister were on the second transport. Their parents chose not to send Lea with them, considering her, at age 4, too young.

Ms. Kugler said that she remembered nothing of the journey through France and Spain and across the Atlantic Ocean, and that any detailed memories of her childhood began with her arrival in the United States. The refugee children wore lanyards with numbered cards — Ms. Kugler was No. 24 — and were placed with foster families. In the years that followed, Ms. Kugler lived in three homes, her sister in four.

“They were difficult and lonely years for me,” she wrote in a memoir, “Shattered Crystals,” co-authored with her mother, Mia Amalia Kanner, and published in 1997.

“Emotionally damaged and traumatized by the Holocaust, I came to America with a hidden disability,” she continued. “With the best will in the world, the members of my foster families had no way of grasping the reasons for my deep unhappiness. How could they comprehend my feelings of isolation, my realization that I was different from other children. How could I explain to them my awful, never-ending feelings of guilt at having been saved at the expense of others, those unknown children who, the day before departure, became too ill to travel?”

She added: “I hid my unhappiness from everyone and cried into my pillow at night.”

Unbeknownst to Ms. Kugler, her parents had survived imprisonment in Nazi concentration camps in France. Lea also had survived, hiding in a Catholic convent and later on a farm. In 1945, Ms. Kugler and Ruth received a postcard bearing the news that they were alive.

Many of Ms. Kugler’s relatives died in the systematic killing of the Holocaust, but the survival of an entire nuclear family seemed, in her description, “miraculous.”

Their reunification in New York the following year, however, was not devoid of difficulty. Ms. Kugler remembered little of her native German. She had been separated from her parents and younger sister for five years. They seemed like strangers.

“My mother very freely told me all of the horrors that went on,” Ms. Kugler recounted. “And it was extremely difficult.”

But together again, they built a new life in the United States. After graduating from high school, Ms. Kugler received a bachelor’s degree in history from Brooklyn College in 1954 before pursuing graduate studies at the University of Pennsylvania.

She was married in 1955 to Joseph Rosenzweig, raised two children and worked as a legal secretary before becoming a journalist, writing for publications including the Village Voice and the Riverdale Press, a weekly newspaper in the Bronx. She later worked in the press office of New York City Comptroller Harrison J. “Jay” Goldin.

Only in her 40s did Ms. Kugler begin to address what she described as a form of “amnesia” surrounding the traumatic events of her childhood.

The experience of writing her memoir with her mother allowed her to better understand her family’s story. She began speaking at schools, synagogues and other venues, committing herself to the preservation of the memory of the Holocaust.

Ms. Kugler’s first marriage ended in divorce. She and her second husband, Simon Kugler, a British citizen, were married in 1991. They had moved together to England, and she remained there after his death in 2010.

In addition to her son, survivors include a daughter, Vicki Rosenzweig, both from her first marriage; two stepchildren, Ralph Kugler and Liz Linton; and two grandchildren.

Ms. Kugler’s father died in 1996 at the age of 97. Her mother died in 2001 at the age of 96. Ruth and Lea both died in 2020.

Ms. Kugler’s death came one day before she was scheduled to participate in the International March of the Living, an annual gathering at Auschwitz, the Nazi death camp in occupied Poland.

“I feel grateful and somewhat guilty,” she once told an interviewer, “for having survived.”