Police in Chicago have launched a murder investigation after a 98-year-old former nurse was found to have died of morphine and hydrocodone toxicity while living in a care home . The Cook County medical examiner has investigated three suspicious deaths at the Holland Home in South Holland , Chicago . Six residents at the care home were all hospitalised on February 3 with former nurse Dorothy Byrd , 98 , Robert Rundin , 88 , and 98-year-old Leon Krynicki all dying . Former nurse Dorothy Byrd , pictured , died from an overdose of morphine and Hydrocodone in February . Frank Shuftan of the Cook County Medical Examiner 's office said Mrs Byrd 's death was caused by morphine and hydrocodone toxicity , combined with hypertensive and atherosclerotic cardiovascular disease . An autopsy performed immediately after Mrs Byrd 's death was inconclusive but further toxicology tests discovered a fatal dose of painkillers in her system . Mrs Byrd 's daughter Sandra Peterson said she can not understand why anyone would want to kill her mother , who was a former nurse . She told Fox Chicago : 'There are n't words that adequately describe the shock and the horror and just the inability to comprehend the who , what , why just many many questions . Mrs Byrd , pictured , was one of six patients to fall ill in February at the Chicago nursing home . 'She loved sweets and so on that day I brought her a couple of slices of cake and some cookies and she just sat there eating it and enjoying it and I left saying I 'll see you tomorrow . ' Ms Peterson said her mother died the following day despite seeming in good form during her visit . The family 's lawyer Tom Paris said : 'She has taught nurses , she 's been a nurse to nurses , she has been a nurse to thousands of patients . Ultimately Dorothy Byrd was betrayed by a nurse . ' According to Mr Paris , the nurse on duty at the time of the deaths has been suspended as have two nursing assistants . Emergency services were called to the nursing home on the morning of February 3 when six patients fell ill. Investigators are preforming further tests on Mr Rundin 's body who died on March 7 , more than a month after he fell ill. David Mills , chief operating officer of Villa Healthcare who run the Holland Home confirmed they are helping authorities with their investigation . A nurse and two nursing assistants from the Holland Home , South Holland , pictured , have been suspended while the investigation into the suspicious deaths continues .
Former nurse Dorothy Byrd , 98 , died of a morphine overdose in February . Mrs Byrd 's daughter visited her mother on the day before she was taken ill. An initial post mortem was inconclusive but further tests found evidence . A nurse and one healthcare assistants have been suspended by the home . The Cook County Medical Examiner 's office found evidence of homicide .