Aren't they doing some underground work there now and a drill hit a solid obstacle underneath the surface?

Yes. http://www.dailymail.co.uk/news/article-2534127/Its-just-pipe-Mysterious-object-blocking-huge-drilling-machine-boring-new-highway-Seattle-identified.html

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
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