sentences:  In the January 2009 sweeps, the hospital is quarantined after one of five toxic spheres detonate during surgery, followed by an anesthesia tank exploding, causing a fire that burns down hospital.The story is used to account for the new hospital set built for the show.Natalia Livingston, previously Emily Quartermaine, returned during this time as Rebecca Shaw, later to be found as Emily's twin sister sold at birth.