Before construction can begin on the new Crossrail station, archaeologists must excavate the 16th-century cemetery that's beneath it. More than 3,300 skeletons, many of whom died from the plague, were exhumed from the old Bedlam cemetery. By taking DNA samples from a plague victim's tooth, scientists are able to study the plague pathogen that caused the death of more than 75,000 people in London and compare it with other samples to see how the disease has evolved over time.Click here to read more: