BOSTON (TheBlaze/AP) — The embattled head of Massachusett’s child welfare agency resigned Tuesday under mounting pressure following the deaths of three children, with Gov. Deval Patrick saying it was impossible for her to continue in her job.

In this Dec. 30, 2013 photo, Massachusetts Department of Children and Families Commissioner Olga Roche speaks during a news conference announcing the department had fired both workers responsible for oversight of Jeremiah Oliver, 5, of Fitchburg, Mass., who had not been seen since September. It was announced Tuesday, April 29, 2014, that Roche had resigned amid mounting pressure after Oliver's disappearance and death, and after two infants in families receiving DCF services had died in April 2014. (AP/Josh Reynolds)

Massachusetts Department of Children and Families Commissioner Olga Roche resigned Tuesday amid mounting pressure after Oliver’s disappearance and death, and after two infants in families receiving DCF services had died in April 2014. (AP/Josh Reynolds)

Olga Roche’s resignation comes after calls from top Democratic lawmakers — including Massachusetts House Speaker Robert DeLeo and Senate President Therese Murray — for Roche to be replaced as commissioner of the Department of Children and Families.

The state’s DCF is also involved in the contentious custody battle involving Connecticut teenager Justina Pelletier, who for more than a year has been in state care after her parents disagreed with a diagnosis made at Boston Children’s Hospital that contradicted another diagnosis and were then met with allegations of medical child abuse. The Pelletiers continue to petition for the department to return custody. It was recently announced that a reunification plan was in the works to at least send Justina back to her home state.

“I have accepted her resignation because I believe it is not possible for the agency to move forward in this environment with her at the helm,” said John Polanowicz, secretary of the state’s Executive Office of Health and Human Services, which oversees the DCF.

The agency named Erin Deveney as its interim commissioner. She has been working there for about 30 days following a stint at the Department of Motor Vehicles.

“Olga Roche presided over the horrific mistreatment of Justina Pelletier and the tragic deaths of children in DCF custody,” the Pelletier’s spokesman Rev. Patrick Mahoney said. “We hope Erin Deveney will correct the systemic injustice of the previous administration by taking immediate steps to free Justina into the loving arms of her family and accepting the reunification proposal.”

Watch WTIC-TV’s report about what this resignation could mean in the Pelletier case:

Authorities say the family of a 2-week old Fitchburg baby who died over the weekend was being monitored by state child welfare officials. In the second case, a DCF spokeswoman says a fax from Grafton police about possible harm to a 4-week-old who later died was misplaced for six days.

The body of a third child, 5-year-old Jeremiah Oliver of Fitchburg, was found off a highway in central Massachusetts this month. Jeremiah’s family was also under DCF supervision at the time of his disappearance.

Massachusetts State Police stand along Interstate 190 where police said a child's body was found Friday, April 18, 2014, near Sterling, Mass. Worcester County District Attorney Joseph Early Jr., said the body has not been positively identified as Jeremiah Oliver, of Fitchburg, but that the height and weight of the body was consistent with Oliver's size. Jeremiah Oliver was last seen by relatives in September 2013 but wasn't reported missing until December. His mother Elsa Oliver and her boyfriend Alberto Sierra are both charged in the case. (AP/Worcester Telegram & Gazette, Tom Rettig)

Massachusetts State Police stand along Interstate 190 where police said a child’s body was found Friday, April 18, 2014, near Sterling, Mass. Worcester County District Attorney Joseph Early Jr., said the body has not been positively identified as Jeremiah Oliver, of Fitchburg, but that the height and weight of the body was consistent with Oliver’s size. Jeremiah Oliver was last seen by relatives in September 2013 but wasn’t reported missing until December. His mother Elsa Oliver and her boyfriend Alberto Sierra are both charged in the case. (AP/Worcester Telegram & Gazette, Tom Rettig)

Patrick, who had earlier defended Roche, said Tuesday that Roche had offered to resign previously, but he had not accepted it. The governor said it was clear now that Roche had the expertise to do her job but no longer had the support of the public or her staff.

“I don’t think the time is right, but it’s necessary,” he said. “She cannot garner the confidence of the public or her line staff.”

Patrick said he was as upset as anyone about the deaths.

“I don’t have confidence at this point in the agency and I’m very worried about the agency,” Patrick said Monday. “My confidence in the whole organization has been rattled.”

Patrick said his top concern is ensuring the welfare of children under DCF care.

Authorities say the family of a Fitchburg baby who died over the weekend was being monitored by state child welfare officials. They say 2-week old Bailey Irish was brought to the hospital on Saturday morning by her parents. She was pronounced dead a short time later.

In an unrelated case, a DCF spokeswoman says a fax from Grafton police about possible harm to another infant who later died, 4-week-old Aliana Lavigne, was misplaced for six days.

The agency said it’s unacceptable that the fax went undiscovered. The department is trying to determine the best method of communicating reports electronically including linking faxes up to email for more timely delivery.

But the agency also said mandated reporters are required to verbally report allegations of abuse or neglect to DCF — something they said police failed to do.

The Grafton police chief acknowledged police should have called DCF, but he also defended his officers, saying the agency is trying to deflect blame.

In the third case, Jeremiah was last seen in September but wasn’t reported missing until December. Police said his death appeared to be a homicide. The boy’s mother and her boyfriend are facing charges in connection with his disappearance but not his death.