On the 03/04/2010 the first blast took place to start the first tunnel for the Blue metro Line's extension under Saltsjon and Sodermalm  in Stockholm: click here to view the video. 

The explosion took place at the London viaduct and marks the start of the 1,250 m long working tunnels. These tunnels will reach down to the future Sofia metro station, 100 m below Stigberg Park. The station will be the deepest in the entire metro network and one of the world's deepest metro stations. A branch of the same work tunnel will end approximately 80 m below Fotografiska. From there, two rail tunnels and a service tunnel will extend north under the Saltsjon to Kungsträdgarden.

Southwards, the tracks will divide and go to a new station under the Hammarby canal, and towards Nacka and also towards Gullmarsplan. For further information please click here and se/91 for the tunnelbuilder archive and also visit https://nyatunnelbanan.sll.se/. 15/20.