Around 4,000 nurses at Brigham and Women's Hospital in Boston went on strike for one day Wednesday, with negotiations over wages, benefits and working conditions still unresolved.

The Massachusetts Nurses Association and Mass General Brigham Healthcare have been negotiating for months but remain at odds. The MNA called the action "the largest nurse and healthcare professional strike in state history."

One of the union's leaders announced that Gov. Maura Healey has called both sides to the State House in an attempt to end the strike.

The nurses' union said they are attending. Hospital management has not yet confirmed its involvement in the talks.

“This is the first time ever, first time in history for a strike at Mass General Brigham,” said Jen DeVincent, a nurse at Brigham and Women’s Hospital.

In a statement, Mass General Brigham said, "We believe the latest offer appropriately recognizes our nurses' important contributions while balancing our responsibility to sustain patient care and our broader mission for the long term."

Nurses voice concerns over staffing, workplace changes Nurse Kristin Robishaw said replacement nurses cannot match the experience of Brigham and Women's staff.

“There is nobody that can replace us. Our team is the best in the world. No replacement nurses are ever going to be able to do the job that we do,” she said.

Robishaw also expressed concerns about the treatment of nurses since the hospital became part of Mass General Brigham.

“We have been taken over by MGB, and we have been treated in a way that the Brigham has never in the history of the MNA treated us,” she said.

Some nurses raised alarms after learning that colleagues were reportedly asked to stay inside due to staffing shortages instead of joining the picket line.

“They were not there as scheduled, so members of our senior leadership team prevented the nurses from leaving, telling them it wasn’t safe,” Robishaw said.

MGB Healthcare disputed these claims, stating that reports of agency nurses not being in place for the NICU shift change were inaccurate.

Hospital extends work stoppage to 5 days Nurse Valerie Ottaviani said she believes the hospital's culture has changed since joining the Mass General Brigham system.

“It has changed a lot since we became a part of Mass General. It’s no longer a healthcare situation, it’s now all about corporate,” she said.

Although the strike is planned for one day, the Brigham is extending the work stoppage to five days to honor contracts with temporary nurses.

The nurses said they plan to remain on the picket line 24/7 until an agreement is reached.

MGB said Francis Street remains open but advised patients to expect heavier traffic near the hospital and plan for extra travel time.

Patient care during the strike MGB has brought in replacement nurses to maintain patient care. The Foxborough Surgery Center will be closed through Friday, but the hospital has advised that all other patients should keep their appointments unless contacted directly by their care team.

Hospital leaders stated that Brigham and Women's Hospital and its outpatient locations will operate largely as normal, though picketing may cause heavier traffic around campuses.

Home care workers also strike Some Home Care services, including dietitian and speech therapy appointments, will be paused during the strike.

Additionally, about 500 Mass General Brigham Home Care workers are also walking the picket lines as they negotiate their first union contract.

Those workers began picketing in Braintree at 8 a.m., with pay, benefits and working conditions remaining key points of contention.

"We are the PTs, OTs, social workers and dietitians. We are fighting for our safety," said Shannon Viera. "What it comes down to, we are forced to work longer hours and provide care for more patients than it is safe."

The workers unionized two years ago but still do not have a contract with MGB.

MGB stated that some home care services will be paused while the strike continues until next week.

"They need to see what we do because sometimes in home health care the outcome is not seen for 6-12 months," Viera said.

Contract talks remain at an impasse Members voted to authorize the strike last week, and a required 10-day notification was sent to MGB.

Gov. Maura Healey said she met with both parties on Monday and urged them to continue working toward an agreement.

"The governor is focused on protecting patients, supporting the health care workforce, and avoiding disruptions to care," a spokesperson for Healey's office said. "She urges both sides to continue negotiating in good faith and reach a resolution as quickly as possible."

According to the union, final bargaining sessions were held last week, but no progress was achieved.

In a joint statement, Boston Mayor Michelle Wu, Sens. Elizabeth Warren and Ed Markey, as well as Reps. Ayanna Pressley and Stephen Lynch urged both groups to return to the bargaining table.

"Nurses are the backbone of our health care system, and we rely on their skills, compassion, and tireless work ethic to care for our loved ones," the statement read. "The nurses at the Brigham and Women’s Hospital and Mass General Brigham Homecare deserve a fair contract that reflects the essential contributions they make each and every day. We urge all parties to return to the bargaining table and reach a good faith agreement that provides stability for this critical workforce, Mass General Brigham, and the patients in their collective care."