. >> it could be jimmy hoffa, it might be the sasquatch. >> spaceships? >> it could be ancient egyptians for all i know. >> reporter: it brings us to the museum of history. so the answer might be in this room. >> the answer might be in this very room. >> reporter: historian lorraine mcconnachey takes us back to the blue collar roots back in the mid-1800s. >> where bertha is now was water. >> reporter: today it's buried by layers of fill leaving some to bonder if bertha's road block comes from seattle's past. >> it could be a locomotive. it could be a steam engine. it could be a boiler. we really don't know what's under there. >> reporter: the process is underway to figure out what's down there. but getting there won't be easy. in fact, it could take weeks to solve the problem. they're currently digging wells to reduce pressure around bertha so it's safe for crews to go down and explore. because bertha is so deep, odds favor a natural blockage like a glacial boulder. >> once we get down there, if it is a boulder, we've got equipment and tools to break it u