JOLIET, Ill. — Nurses in Joliet returned to work Saturday morning after a four-day lockout.

The Illinois Nurses Association said members at Ascension St. Joseph Medical Center in Joliet were locked out since Tuesday morning.

It happened after the union threatened a two-day work strike over wages and working conditions.

Ascension said it’s contractually obligated to replace nurses for at least four days during any planned strike.

Some nurses tried to return to work on Thursday but were turned away.

Contract negotiations have been going on since May with little progress.

They’re set to resume Sept. 8.