The woman and the children were not identified, and her relationship to the victims was not disclosed.
“This is an unimaginable, senseless tragedy,” Cruz said.
Massachusetts General Hospital officials confirmed Wednesday that the woman was employed there.
“We are shocked and saddened to learn of this unthinkable tragedy,” the hospital said in a brief statement. “We extend our deepest sympathies to all those affected by these devastating events.”
On Wednesday afternoon, two Plymouth women, Donna Jesse, who identified herself as an aunt of the children, and Rita Musgrove, who said she was their great grandmother, were both visibly emotional as they approached the house and left a bouquet of pink, red, and white roses with other flowers that people had placed outside the residence.
“They were beautiful, beautiful children,” Jesse said.
Musgrove said that “it’s pretty shocking.”
Cruz declined to disclose further details, citing the ongoing investigation, but described the woman as a suspect in the deaths of the children. A press conference is scheduled for 3:30 p.m. Wednesday at the Duxbury police station with the district attorney and other law enforcement officials, authorities said.
The woman was rushed to a hospital where she was undergoing treatment Tuesday night, Cruz said. Officials said she remains hospitalized.
The state medical examiner’s office has now accepted custody of the two deceased children and will conduct autopsies to determine the cause and manner of death. Findings will be made public when a death certificate is issued, according to the Office of Chief Medical Examiner.
Two police cruisers were parked in the driveway of the Summer Street house Wednesday morning, but there was no other outward sign of what authorities said took place inside the single-family home.
A Kia SUV was parked in the driveway with sticker on the back reading, “Baby on Board.” Nearby was a boat, wrapped for the winter season.
A swing set was visible in the back yard, along with a green slide, a soccer ball, and a toy wheelbarrow behind a white picket fence.
John Sullivan, a neighbor whose yard is adjacent to the back yard at 47 Summer St., said he got a call Tuesday night from his son who told him a woman “was laying down in the backyard.”
Sullivan headed over to his neighbor’s property where he saw first responders performing CPR on a baby outside.
”Right outside, right in the driveway, about 20 feet from the house,” he said.
Sullivan said he didn’t know the neighbors well but never saw any signs of trouble coming from the home.
Tom McGrath lives nearby and was walking his dog on Summer Street. He said he passes the house every day and was shocked to learn about what had happened.
“It’s sort of like, how can this happen around here?” he said.
McGrath said he will be thinking about the young victims and offered his prayers.
“Especially for the baby,” he said. “And prayers for what she was going through to actually do this.”
Radio transmissions on the website Broadcastify provided a chilling account of what first responders discovered when they arrived at the Summer Street home.
“We’ve got three pediatric arrests,’’ a firefighter said at one point.
”Three pediatric arrests,” the dispatcher responded. “We’ve got mutual aid on the way.”
The transmissions between firefighters on the scene also gave a sense of the life-saving efforts they were undertaking.
“Cap,” a firefighter asked of the captain in command. “Can you get one of the cops to help us with compressions so we can do some other stuff.”
A few minutes later, first responders had placed the four patients into four ambulances and the commander on the scene updated the dispatcher.
Earlier, according to Broadcastify, a dispatcher reported that the woman “jumped off the top floor of the house” and had injured herself before the fall. “She’s conscious. … It was over a 20-foot fall.” The dispatcher also said the woman sustained back injuries and neck lacerations.
On Twitter on Wednesday morning, the Duxbury Fire Department wrote that public safety resources from six towns were part of the response to the home.
“Thank you to all the agencies who supported us during the last 12 hours. We used resources from six towns to help us in our response to this tragedy,” officials said. “Please keep the family and all the first responders in your prayers.”
The Kingston Fire Department, whose ambulance crew drove one of the children to the hospital, described the case as a “horrific tragedy” in a Facebook post Wednesday.
”Last evening Kingston Firefighter/Paramedics responded to the horrific tragedy that occurred in Duxbury. We are proud to stand with our neighboring communities and provide any support needed,” the Fire Department said. “Please keep the family and all those who responded in your thoughts.”
It’s hard to find the right words for the unimaginable tragedy in Duxbury last night. Our hearts break at the loss of these innocent children. There is lots of love and support in our community and every bit of it will be needed for this family.
— Rep. Josh S. Cutler (@joshscutler) January 25, 2023
At a news conference Tuesday night, Duxbury Police Chief Michael Carbone said the tragedy was not random and “there is no further threat to the community.”
On Wednesday, St. Paul’s Church of the Nazarene on Summer Street said it would open its doors for prayer until 7 p.m.
“If you are in need of pastoral support or would like a place to pray for this family, those involved or the greater Duxbury community as a whole, you are welcome,” the church said on its official Facebook page.
Inside the church foyer Wednesday afternoon, tables were set up with food and refreshments.
“We wanted to open our doors to make sure there was a place for first responders or people who needed prayer, or just a safe place, a quiet place, to contemplate things to be able to come and just reflect or talk to someone about the events that have just happened in our community,” said Rachel Pitot, a church volunteer.
Reverend Bill Ferguson, senior pastor of Pilgrim Church of Duxbury, said in a video message posted to Facebook that the town’s community will come together to support one another in their grief.
”Friends, we are at a place, at the moment, when all we can do is to walk together in our discomfort and confusion, carrying with us our unanswered questions and our grief, asking God to be with us,” Ferguson said.
The police presence Tuesday night startled neighbors in the affluent South Shore town.
Francis Turner, 77, who has lived around the corner from the Summer Street home for about 40 years, said he saw “a bunch of police cars” outside his home Tuesday night and went outside to see which house was at the center of the emergency response.
“They just told me to stand back further,” Turner said of the police. “I just turned around and went back home. You really couldn’t see what was going on.”
Turner said he has never met the family living at 47 Summer St. His daughter told him they had “just moved in not too long ago.”
This is a developing story and will be updated. John Hilliard, Jessica Bartlett, and John Ellement of the Globe Staff contributed to this report.
Emily Sweeney can be reached at [email protected]. Follow her on Twitter @emilysweeney and on Instagram @emilysweeney22. John Hilliard can be reached at [email protected]. Travis Andersen can be reached at [email protected]. Follow him on Twitter @TAGlobe.