Thousands of Kaiser Permanente health care workers in Southern California and beyond are returning to work today following a three-day strike billed as the largest of its type in U.S. history.

Workers started returning as of 6 a.m. Saturday and officials with the Coalition of Kaiser Permanente Unions and the healthcare provider said contract negotiations are set to resume Thursday.

However, the unions said they may issue a 10-day strike notice Saturday, potentially setting the stage for further walkouts if a contract agreement is not reached.

Kaiser officials said the next “large, in-person bargaining session” is scheduled for Thursday, although in the meantime, “committees and local bargaining teams representing both sides will continue to meet.”

Early Saturday, Kaiser officials said they were happy to have the health care workers back on the job.

“We are pleased to welcome back our employees who participated in this week’s strike,” the statement from spokesman Terry Kanakri said. “With the current strike behind us as of 6 a.m. today, our collective focus  (will) return to normal operations.”

Kaiser members can find more details at the website.

Meanwhile, the unions said they remain committed gaining improved working conditions and better salaries for the workers they represent.

“As frontline healthcare workers conclude the current strike action on Saturday morning, our resolve to advocate for the safe staffing that our patients need has never been stronger,” Georgette Bradford, an ultrasound technician from Sacramento who is a member of the union’s bargaining team, said in a statement released Friday by the union.

An estimated 75,000 Kaiser workers took part in the strike, according to the Coalition. In addition to California, picketing took place in Colorado, Washington, Oregon, Virginia and Washington, D.C.

The coalition has been pushing for higher wages commensurate with inflation, increased staffing and working conditions. The unions have also repeatedly accused Kaiser of negotiating in bad-faith, an allegation Kaiser has denied.