An estimated 10,000 people work at Boeing Field. So it makes sense that the company would be dismayed if one of the primary routes leading to it were to close. As it turns out, that scenario is no longer hypothetical.In case you haven't heard, King County will be shutting down the South Park Bridge on June 30 pending the results of a Road Services study on whether it's fit for continued use. This was not an unexpected development. But the news has left political leaders scrambling to come up with a contingency plan.As for Boeing, the aerospace giant's outcry has been largely nonexistent.Boeing spokesperson Bernard Choi says that while the company has been receiving regular updates from King County on the bridge's status, its ultimate fate is largely out of the company's control.To what degree the bridge's closing presents a problem for Boeing is unclear. Layoffs have reduced the number of employees who work at the Tukwila campus. But Choi notes that along with the Boeing workers who use the bridge, the truckers who make supply drops at the facility will also have to use alternative routes.Asked if the company had identified such an alternative, Choi let drop that they have some "contingencies that work," but declined to go into details.Back in 2007, Boeing threw its weight behind a $47 billion transportation proposal that would have freed up necessary funds to replace the bridge. Voters didn't approve it, however.Seen in light of Microsoft's recent shot across the bow of the S.S. McGinn over the mayor's 11th-hour suggested edits to the plan to replace the 520 bridge (the company bought a full-page ad in The Seattle Times and held a news conference), Boeing's quiet reserve is that much more puzzling.