The family of an assisted living facility resident who died after an alleged morphine overdose plans to sue the facility, according to CBS Chicago.

Dorothy Byrd was one of six residents at Holland House in South Holland, IL, who were taken to the hospital last year with morphine in their systems last year. Byrd’s death from morphine and hydrocodone toxicity was later ruled a homicide. Two other residents also died.

The lawsuit, which CBS reports the family plans to file on Thursday, alleges that the nurse on duty that night administered morphine to residents to “ease her workload.” The suit also claims the nurse had inadequate training and had an expired nursing license.

Villa Healthcare, which manages Holland House, did not respond to McKnight’s request for comment by press time. In a statement to CBS, Holland House officials said the company is taking the situation “extremely seriously” and are cooperating with investigators.