The initial cost of the tunnel project was estimated in 1984 to be $334.6 million, but the final costs rose 56% over budget to a total of $468.7 million (equivalent to $ in dollars); the project's cost overruns were blamed on unanticipated soil conditions on the approach to Pine Street from 3rd Avenue, complaints and payouts to downtown businesses disrupted by tunnel construction, and the death of an electrician during construction. Excavated dirt from the project was used as fill for runway expansion at Paine Field in nearby Everett.