Sad news from the pages of this morning’s New York Times:

Behind the red-brick walls encircling the Convent of Mercy in Brooklyn, generations of nuns have taught the illiterate, sheltered the homeless and raised orphans. They are known as the Walking Sisters, ministering in the community as well as inside their convent.

Now, after 146 years, it is time for the small band of sisters, most of them retired, to walk away from the convent. The leadership of their order, the Sisters of Mercy, decided to shutter the place and scatter the sisters to other homes and nursing facilities after realizing it would cost more than $20 million to fix serious structural and accessibility problems in the fortresslike building on Willoughby Avenue in Fort Greene.

This has been a season of heartbreak and anger for these women, who thought the motherhouse would be their last home and the sisters their constant companions. Now they, the rescuers of lost children, feel like orphans themselves.

“It kind of hurts in a lot of ways,” said Sister Francene Horan, who came to the motherhouse in 1950 to teach kindergarten. “A building is one thing. This is a home, the place you knew would give you a place to stay. It’s like saying your parents died and you don’t have a home anymore.”

In a ritual that was unthinkable a year ago, they gather regularly as their numbers dwindle to bid goodbye to one another, and to an entire way of life — the busy convent and its shared days of work, prayer and laughter.

The Sisters of Mercy, known as the Walking Sisters because working outside the convent was unusual for nuns in the 19th century, have been in Brooklyn since 1855, when five young nuns from Manhattan answered Bishop John Loughlin’s call to work with the poor and sick. They went from the ferry at Fulton Landing to the nine-room convent of St. James parish on Jay Street, where they lived and worked.

Legend has it that five boys were left in their care one day, not an uncommon occurrence during a time when illness often claimed the lives of work-weary immigrant parents. As the nuns’ work grew along with their reputation, they moved in 1862 to the much larger quarters of their present convent, in what was then a solidly Irish neighborhood.

Thousands of children came to live with the sisters over the decades. Rather than fend for themselves as ragamuffins, they lived in tidy dormitories, supervised by two nuns and a helper. In the chapel, an ornate sanctuary of stained glass and gleaming marble, the youngest had a place of honor at the front, sitting in pews that were smaller than the rest.

Mary Margaret McMurray was almost 6 years old when she and her sister arrived at the orphanage after their parents died of influenza in 1917. She stayed until she graduated from high school and took a job as a secretary at an insurance company.

“The convent was so big,” said Ms. McMurray, now 97 and living in Queens with her daughter, herself a Sister of Mercy. “And there were so many children there. I had a lot of company. But it was very pleasant.”

The nuns taught her a lot, she said, and not all the lessons were found in books. “They taught me to be a positive person,” she said. “And of course, religion, too.”

Read on for more. Also, check out the poignant slide show of pictures at the Times link.

Photo: Sister Camille D’Arienzo at the Sisters of Mercy’s motherhouse in Brooklyn, which will be closed and possibly torn down by developers. Photo by James Estrin, New York Times