Complex sentence: Four survivors of the slide were still in Seattle-area medical facilities with two of the four admitted to intensive care, one remained in stable condition at Harborview Medical Center, and another had been discharged from Harborview to a rehabilitation facility.
Split into simpler sentences: Four survivors of the slide were still in Seattle-area medical facilities. Two were in intensive care and one in stable condition at Harborview Medical Center; one person had been discharged from that center to a rehabilitation facility.