Workers digging London's Crossrail tunnel have helped uncover a 350-year-old mystery about the Great Plague:
[T]he Great Plague...killed 100,000 Londoners (roughly a quarter of the city’s population) around 350 years ago.
Last year, workers constructing a future new ticket hall at Liverpool Street Station unearthed a charnel pit adjoining the old Bedlam Hospital, in which 3,000 skeletons were interred. Now it turns out that some of these skeletons had the answer to a centuries’ old mystery, hidden away in their teeth.
Scientists at Germany's Max Planck Institute took samples from the teeth of 20 of these corpses, and this week confirmed what historians have long suspected but been unable to prove: London's Great Plague was caused by the Yersinia Pestis bacteria, exactly the same pestilence that killed around one-third of Europe's population in the 14th century, under the name the Black Death.
The BBC has more.