2008: Minnesota Nurses Association breaks off from the American Nurses Association, saying its members want a more forceful union that will represent the economic interests of bedside nurses.
March 2010: Nurses and 14 Twin Cities hospitals begin contract talks for a new three-year agreement. Hospitals seek concessions on pensions, health insurance and nurse staffing rules.
May 6: Nurses stage informational picketing, saying their proposal for formal nurse staffing ratios would improve patient care and hospital safety.
May 19: Nurses reject hospitals' offer and authorize a one-day strike.
June 4: Contract talks break down.
June 10: Nurses stage a 24-hour walkout at the 14 hospitals.
June 21: Nurses vote to authorize an open-ended strike, later set for July 6.
June 23: Federal mediator calls negotiators back to the bargaining table.
