Supporters of Prouty Garden, a historic healing garden at Boston Children's Hospital, have asked Massachusetts Attorney General Maura Healey to block the hospital from demolishing the garden to put up a new clinical building.

The group Friends of Prouty Garden filed a letter and large packet of documents with the attorney general's office, asking that the division that deals with nonprofit organizations and charities take up the case.

The group's attorneys, Greg McGregor and Michael O'Neill, argue that the garden was a charitable gift to Children's Hospital and to destroy it would be a "violation of the terms" of the gift. They say the attorney general has the authority to enforce state laws surrounding such charitable gifts. The attorney general's office confirmed they received the documents, but declined to comment further.

Novelist and poet Olive Higgins Prouty bestowed the garden in 1956 in memory of two of her children who had died. Prouty had previously funded a ward at the pediatric hospital, but when the hospital demolished that building she funded the new 0.5-acre garden, overseeing its design and upkeep.

"The hospital asked her to create the garden and asked her to endow it upon her death, and she agreed, on the terms that it be in perpetuity," McGregor, the garden supporters' attorney, says. He adds that letters between Prouty and hospital administrators, a section of her will and a plaque in the garden itself prove the site was to remain perpetually. The plaque reads, "Because of Mrs. Prouty's vision, this garden will exist as long as Children's Hospital has patients, families and staff to enjoy it."

Esther Morales stands near the entrance to Children’s Hospital with a group protesting the removal of the proposed demolition of the garden. (Robin Lubbock/WBUR)

More than 11,000 people have signed a petition to save the garden from demolition. They include hospital patients, family members and staff who call the garden sacred ground and an important part of the process of enduring often difficult medical treatments. Many families have brought their children to the garden to spend their final moments of life. At least one family scattered its child's ashes on the site.

"This is part of the healing that we have to offer, part of the therapy that we have to offer," says Elaine Meyer, a clinical psychologist who directs an institute on ethics at the hospital. "This is not just any garden. This is a memorial garden, and we have a promise to uphold."

The hospital plans to build a new 11-story clinical building on the site of Prouty Garden and the Wolbach Building, which is also slated to be torn down. Hospital administrators say the new building is necessary to create a state-of-the-art neonatal intensive care unit and a new pediatric heart center, as well as private rooms so that there will be no more double patient rooms at the hospital.

Hospital administrators did not respond to requests for comment on the garden supporters' filing with the attorney general. But in a recent interview, the hospital's chief operating officer and executive vice president of health affairs, Dr. Kevin Churchwell, told WBUR hospital officials closely reviewed several other possible sites for the new building and none of them was viable.

Near the spreading roots of a redwood tree visitors relax in the Prouty Garden. (Robin Lubbock/WBUR)

"The most important thing we do here is take care of children who need us desperately. And that care is provided by our caregivers — nurses, doctors — and the [building] space," Churchwell said. "And if the space is not where it needs to be, that's an important issue we need to deal with."

Hospital leaders say they're working to create new green space scattered throughout the property, including a rooftop garden and indoor gardens. They say the facility will end up with more green space than it currently has.

Members of the group trying to protect Prouty Garden say none of those spaces will come close to the mature healing garden, which includes a 65-foot dawn redwood tree and areas for privacy. They say they agree with the hospital's need for the new building but believe the hospital can find another site.