Sister Megan Rice

ROSEMONT, Penn. — Megan Rice, a nun and Catholic peace activist who spent two years in federal prison while in her 80s after breaking into a government security complex to protest nuclear weapons, has died. She was 91.

Rice died of congestive heart failure Oct. 10 at Holy Child Center in Rosemont, Pa., according to her order, the Society of the Holy Child Jesus.

“Her commitment to build a peaceful and just world was unwavering and selfless,” said Carroll Juliano, American Province Leader for the order.

Rice was born in New York to activist parents who would meet with well-known Catholic writer Dorothy Day during the Great Depression to craft solutions for societal problems, she said in a 2013 interview.

Her activism was also heavily influenced by her uncle, who spent four months in Nagasaki, Japan, after it and Hiroshima had been leveled by atomic bombs to hasten the end of World War II, bombings that Rice would later call the “greatest shame in history.”

While still a teenager, she entered the Society of the Holy Child of Jesus to become a nun. She made her final vows in 1955 and took on the religious name Mother Frederick Mary. Rice later earned degrees from Villanova and Boston University.

She taught schools, including 23 years in West Africa. When she returned to the U.S., Rice began her involvement in anti-nuclear activism.

“I felt drawn to the peace movement,” she said.