CLEVELAND — Dominican Sister Ardeth Platte long considered herself a peacemaker and devoted nearly 40 years of her life to praying and witnessing to end war and rid the world of nuclear weapons.

Her actions led to imprisonment multiple times, including for the 2002 defacement of a missile silo in Colorado in collaboration with her best friend, Dominican Sister Carol Gilbert, and fellow Dominican Sister Jackie Hudson.

Platte, 84, died in her sleep at the Dorothy Day Catholic Worker House in Washington early Sept. 30. Funeral arrangements were pending Oct. 5 because of the coronavirus pandemic.

Gilbert told Catholic News Service she discovered her friend in bed, still wearing headphones after apparently listening to the radio.

The death shocked Gilbert.

“She was fine. Ardeth listened to the (presidential) debate Tuesday night. She usually listened to them laying down in bed,” Gilbert said.

Gilbert was waiting for her friend to awaken that morning so she could tell her that Malaysia overnight had become the 46th nation to ratify the Treaty on the Prohibition of Nuclear Weapons. Fifty nations must ratify the treaty for it to go into force.

The two Michigan natives and members of the Dominican Sisters of Grand Rapids spent decades crisscrossing the United States opposing war and acting to bring life to the biblical call to “beat swords into plowshares” by symbolically disarming nuclear weapons and other tools of war.

In 2012, they told CNS there was no better calling in life.

Gilbert said that as recently as Sept. 26, designated by the United Nations as International Day for the Total Elimination of Nuclear Weapons, her friend continued her quest for peace by addressing an online Boston University program marking the day. She also joined a quiet protest that day near the Dorothy Day Catholic Worker, holding a sign urging passersby to support nuclear disarmament.

The nuns met in the mid-1970s in Saginaw, Michigan, where they were teaching. Sister Platte was principal of St. Joseph High School in the working-class city. She had seen how crime and violence were claiming the lives of young people. In response in 1967, she founded and directed St. Joseph Alternative Night School for youth and adults who wanted to complete their high school education.

Platte also began questioning the Vietnam War after seeing many of the city’s young people who managed to avoid trouble face unemployment and end up in the armed forces, fighting in Southeast Asia. She saw many return home maimed or killed.

Meanwhile, Platte’s work as an educator impressed community leaders, who urged her to run for Saginaw City Council. She served as a council member from 1973 to 1985.

She also was coordinator of the Saginaw Home for Peace and Justice for more than 10 years.

The turning point for Platte and Gilbert came when they attended an international conference on nuclear disarmament in 1978 in New York, where they heard from prominent nuclear disarmament proponents, who urged attendees to address the challenges such weapons posed.

The sisters embarked on a 40-day trek across the country visiting and praying at nuclear weapons related sites.

“It was a spiritual journey,” Platte later recalled to CNS. “The journey escalated us into the vow to spend the rest of our lives ridding the world of nuclear weapons and stopping war forever.”

During the 1980s, the nuns worked with a statewide peace coalition on a ballot initiative that would have prohibited nuclear weapons from being deployed in the state. Although it passed with 56 percent of the vote, federal law superseded state law, allowing for the deployment of nuclear weapons at two now-closed Air Force bases in northern Michigan.

In 2000, Platte, Gilbert and Hudson undertook the first of their Plowshares actions when they illegally entered Peterson Air Force Base in Colorado Springs, Colorado, and sprayed a fighter plane with their blood. They were arrested and jailed, but charges eventually were dropped.

Not long after, in 2002, the trio cut a fence to gain entry to a Minuteman III nuclear missile site near Greeley, Colorado. They prayed in front of the silo and then poured blood on it.

Closely following the events of 9/11, federal prosecutors charged them with obstructing national defense and damaging government property. They were convicted and sentenced to between 30 and 41 months in federal prison.

The imprisonment did not deter Sister Platte as she continued to oppose war and periodically faced arrest and jail.

The nuns’ imprisonment also led to their advocacy for reforms in the operation of federal prisons. Their efforts were the subject of a 2006 documentary, “Conviction.”

Born on Good Friday, April 10, 1936, in Lansing, Michigan, Platte entered the Dominican order in 1954 at age 18 and was a member of the order for 66 years. She received a teaching degree from Aquinas College in Grand Rapids.

The two friends moved to the Jonah House community in Baltimore in 1995, where they continued their nuclear disarmament work with fellow Plowshares activists. They moved to the Catholic Worker community in Washington in December 2018.