In an update to the ongoing work to save the West Seattle Bridge, the Seattle Department of Transportation prepares for a potential closure of the lower Duwamish Waterway bridge, as well. SDOT asked the city’s departments to make preparations in the event the second bridge closed.

Since the abrupt closure of the West Seattle Bridge, cracks in its foundation only continued to spread. The fissures in its concrete girders caused SDOT to schedule emergency maintenance.

While the structural threat continues to grow, the department’s director Sam Zimbabwe told City Council on Monday the bridge isn’t anticipated to collapse. “It’s still our assessment that the bridge is not at imminent risk of failure,” he said.

Still, needed repairs face uncertainty. The department is uncertain whether they have the ability to stabilize the West Seattle Bridge in order to complete necessary work to sustain it. Such efforts would need to take place prior to repairs, and in advance of a possible collapse.

SDOT Warns of Possible Worst Case Scenario

In the event of an imminent collapse, which the department considers worst case, they would close the lower bridge out of safety. While not directly beneath, it’s proximity poses a threat to those crossing over it.

At present, the lower bridge only sees use from emergency vehicles, freight, buses, and, longshore workers, as well as the occasional driver shirking restrictions. Still, the lower bridge sees 15,000 passing cars daily. Any closure requires those travelers seek alternative routes, a tricky contingency to work up.

But that’s precisely what the city is tasked with doing in order to prepare for such a scenario.

SDOT and collaborating engineers work out how to determine an imminent collapse. Additionally, they plan to implement sensors in May.

In the meantime, the bridge remains open. Limited traffic may still use it.