April 4, 2018 marks the first anniversary of Bertha's breakthrough at the North Portal site of the SR99 Tunnel in Seattle, Washington. The 57.5ft EPBTBM, built by Japan's Hitachi-Zosen, is the world's largest diameter tunnel boring machine to complete an underground drive. The new tunnel will replace the Alaskan Way Viaduct and provide safe passage along the city's vibrant waterfront adjacent to downtown.