Bertha, the world's largest tunnel-boring machine, struck an eight-inch-diameter, 119-foot-long steel pipe in early December, officials revealed last week. The steel pipe brought the 57-foot-wide behemoth to a halt and caused severe damage to the machine's cutterhead.

But that's just the beginning of troubles for the controversial state megaproject. At a press conference last Friday, state officials acknowledged the pipe was placed there by a state-hired contractor in 2002 during the early stages of the highway replacement project. The pipe was not removed as it should have been, thereby ultimately placing fault with the state for leaving the metal shaft behind and then sending a tunneling machine into its path.

That pipe may be just one of many obstacles. Crews have since sampled the soil ahead of the stalled machine and discovered more metal obstructions lodged in the tunnel digger's path, which all must be removed before Bertha can proceed.

But when reporters peppered project managers with questions, they conceded there is currently no plan or timeline for removing the objects located more than 60 feet below downtown, raising concerns about possible delays, cost overruns, and who will foot the bill if the $4.2 billion project to replace the Alaskan Way Viaduct runs over budget.

Right now, it's not even clear what else may be blocking Bertha.

"We have probed 12 holes and encountered other obstructions in six of those holes," said Chris Dixon, the program manager for Seattle Tunnel Partners, which has a $1.4 billion contract with the state to dig the tunnel. (His company is not the same contractor that installed the pipe 11 years ago.) The obstructions are not believed to be boulders or timber, Dixon said, leading him to believe they are "metal objects." The tunneling machine's face can churn though soil and break boulders, but it cannot chew through metal. (For its part, the Washington State Department of Transportation, which is responsible for the project, claims that out of 17 soil samples, there were only four obstructions.)

"We need to remove the other pieces of metal so we do not cause further damage to the tunnel-boring machine," said Matt Preedy, the state's deputy program administrator for the project. "We don't want to push the limit with this thing." The multimillion-dollar machine has completed about one-tenth of its route and must remain in working order, he said, adding that officials don't know "if the pipe is the only issue or one of several," and it would take "a little while to explore" the situation.

It's fair to say that this amounts to a colossal setback for the megaproject—one that many worried would become a boondoggle.

The deep-bore tunnel is the largest part of the viaduct replacement project, a four-lane underground freeway that was the subject of controversy during planning stages due to speculation of unprecedented logistical hurdles, cost overruns, financing problems, and delays. Already a labor dispute stalled the project for a month last fall, in addition to this latest monthlong pause. Meanwhile, a contingency fund originally proposed at $415 million is only $40 million after inflation and other drains, shrinking the margins for affordable errors. The project budget also requires $400 million from future tolling revenue, but latest projections show the state may collect only about $165 million. All of these setbacks and shortfalls raise red flags—particularly when just a fraction of the tunnel has been dug—because state law prohibits spending additional money if the project runs over budget.

Typically, tunneling megaprojects run 34 percent over budget, according to a report by Bent Flyvbjerg, a Danish professor at the University of Oxford. But former governor Chris Gregoire's transportation secretary insisted in 2009, "There won't be any cost overruns." And Seattle City Council member Tom Rasmussen, a tunnel backer who chairs the council's transportation committee, claimed in 2010 that project bids "should put the question of cost overruns to rest."

But the overrun issue is wide-awake these days.

As the Tacoma News Tribune titled an editorial on December 30, "If Bertha gets snagged, don't send bill to the state." State law says that Seattle must bear all cost overruns, a statute that many claim is unenforceable but may be subjected to politics in the legislature, which is famously vindictive toward Seattle. The Tribune warns of "overruns to the tune of hundreds of millions of dollars," adding that when it comes to the law requiring Seattle to pay overruns, "the legislature has made its intent clear—and lawmakers should make certain it does get enforced."

The state and Seattle Tunnel Partners still refuse to answer many key questions: cost per day of delay, why the metal pipe was not removed before drilling, the nature of changes to contracts since digging began, or how many days of stalled operations the project can handle before running into delays and cost overruns. Officials stonewalled or feigned ignorance on the answers.

Trouble began on December 3, when Bertha struck the vertical pipe, which was part of a well originally designed to measure the groundwater when the state first considered the viaduct replacement, but officials decided to continue plowing through the pipe anyway. "The fact that [Bertha] performed well for two days [after first hitting the pipe] gave us a false sense of security," said Dixon. Two days later, the machine was too belabored to proceed. "Tunnel-boring machines do not interact well with metal," he continued. "The cutterheads cannot cut steel."

Grinding through the metal with its six-story-high rotating face of gnashing blades, the cutterhead sustained "unusual damage" to many of those cutting tools, said Dixon. He said it takes several hours to replace each tool, and "the device has hundreds of tools."

Dixon said, "We did not know the pipe was there" because such objects are "usually... decommissioned from the ground."

Speaking for the state, which was ultimately responsible for removing the pipe, Preedy said the state knew about its location. "The location of the well [pipe] was described in certain documents." But as for contracts to remove that pipe and whether the state may incur liability for failing to remove it, he said, "We don't want to talk about contracts." recommended