world wars and the steam ships that crossed the golden gate. the bethlehem shipyard was one of the largest shipyards in the country and helped build sections of the transbay tube for b.a.r.t. and bethlehem iron workers also risked their lives to build the golden gate bridge. >> they paid us in gold every week, they figured we wouldn't go out there. >> reporter: a look at the past of san francisco's shipyard and what the future may hold. >>> hello everyone i'm frank somerville and welcome to a second look. this evening we take a look at pier 70. the longest continuously operating shipyard any where in the country. but now, much of that land is slated for redevelopment. pier 70 sits on san francisco's eastern waterfront. the 65-acre site has fallen into disrepair although one portion remains a working shipyard. how are it was once the largest shipbuilding operation any where on the west coast. since the gold rush. ships have been built in the waters near potrero hill.