There is mystery surrounding a major work in progress – a tunnel that has literally struck a snag of unknown origins.

They call this tunnel machine – Bertha, a 57-foot-wide, earth-eating tunnel maker tearing away dirt and debris below downtown Seattle to make way for an underground highway along the city’s waterfront.

The contractors responsible for drilling that tunnel under downtown Seattle say so much groundwater is flowing into the tunnel it will take another few weeks before they can look at what’s blocking Bertha.

Chris Dixon of Seattle Tunnel Partners told The Seattle Times that a sealed-off chamber is almost full of water, even though six wells have been dug to try to pump water away from the machine.

“We’re a bit puzzled about what’s preventing us from moving forward,” said Chris Dixon with Seattle Tunnel Partners.

A mysterious obstruction, 60 feet down, and Seattle is abuzz with theories of what’s in Bertha’s way.

“There’s history buried everywhere,” local historian Feliks Banel said. “It could be Jimmy Hoffa, it might be Sasquatch or it could be a flying saucer, you know.”

The area where Bertha is stuck was once under water. The object blocking Bertha’s path may be a remnant of Seattle’s industrial roots, Lorraine McConaghy, a historian with Seattle’s Museum of History and Industry said. There was a steam-powered sawmill in the area in the mid 1800’s.

“It could be just about any industrial artifact you can imagine that might have ended up in the water,” McConaghy said, adding the possibilities included a locomotive or boilers and engines used in the old mill.

Laura Harper, a history teacher from Yakima, Washington agreed, “I’m assuming there’s probably an underground building, a ship, some sort of artifact from maybe 100 or 200 years ago,” she said.

Construction workers believe it is probably just a big boulder that was washed down in the glacier melt, but nobody knows for sure.

“There’s thousands of guesses what’s going on, but until we get down there and see what the actual situation is, it’s just speculation and guesses,” Dixon told a news conference last week.

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