Updated

Frightening fiction could be closer to reality for the Pacific Northwest.

A newly released video from Washington's Department of Transportation simulates what a catastrophic earthquake would do to the Seattle waterfront.

The simulation details the potential effects of a magnitude seven quake taking place about 20 miles off the coast — similar to a 2001 tremor that rocked the region.

Analysts say the sea wall would give way, and the double-decker highway next to it would collapse. Snapped gas lines would spark fires. And power and communications would be cut off to most of the city.

Washington state's Department of Transportation was reluctant to release the clip, completed in 2007 fearing that the video was too violent and sensational. But a private citizen filed a freedom of information request, and now the video has been made public.

Release of the video has become a political battle, as city and state officials moved ahead over the weeekend with a plan to replace the viaduct. Candidates for Seattle mayor are battling over support for a replacement tunnel.

The Seattle Times reports that Mayoral candidate Mike McGinn questions the timing of the video's release — and noted the video was produced by a tunnel contractor linked to his opponent, Joe Mallahan. A Mallahan campaign spokeswoman called such suspicions laughable.