The Massachusetts Nurses Association is initiating the largest nurses strike in state history. 

As of this morning, about four-thousand union nurses at Brigham and Women's Hospital are walking out.  This comes after months of failed negotiations between the union and the state's largest health care system.  The strike is only scheduled to last one day, but nurses will be locked out of the hospital for an additional four days, returning on July 13th. 

The union is demanding a three-percent pay raise for the first six months and a four-percent raise for the following 12 months of the contract.