Construction workers building a new east to west railway line in London have stumbled upon a burial ground containing over 3,000 skeletons, AFP reports. Archaeologists have now started excavating the remains, some of which belong to victims of the Great Plague of London.

In close proximity to Liverpool Street station, one of the English capital’s busiest transport hubs, a team of 60 researchers work in shifts to dig up the bones, which are set for reburial at an East London cemetery.

Crossrail, the company charged with building the railway, announced in a statement that the Museum of London’s archaeology department was carrying out the dig on the firm’s behalf. A spokesperson for Crossrail added, “Archaeologists hope that tests on excavated plague victims will help understand the evolution of the plague bacteria strain.” In addition, the bones could “shed light on migration patterns, diet, lifestyle and demography,” of early Londoners.

The so-called Bedlam burial ground was used between 1569 and 1738 and was the final resting place for those who could not afford a church burial or who chose not to for political and religious reasons, like members of the Levellers, a 17th-century political grouping that advocated popular sovereignty and religious tolerance.

According to Crossrail’s lead archaeologist Jay Carver “This excavation presents a unique opportunity to understand the lives and deaths of 16th and 17th century Londoners. The Bedlam burial ground spans a fascinating phase of London’s history, including the transition from the Tudor-period City into cosmopolitan early-modern London.”