 Complete the following phrase:  During the construction of Kerameikos metro station for the expanded Athens Metro, a plague pit and approximately 1,000 tombs from the 4th and 5th centuries BC were discovered. The Greek archaeologist Efi Baziotopoulou-Valavani, who excavated the site, has dated the grave to between 430 and 426 BC. Thucydides described the panic caused by the 