SEQUIM — The Dungeness River Bridge was closed today after flood-strength waters knocked loose several of its support pilings and threatened the collapse of the western walkway portion of the bridge.

Concern is focused not on the iconic steel railroad bridge itself across the Dungeness — it is anchored in concrete at both ends — but on the bridge’s old trestle portion which continues across the west side of the river.

The old railroad trestle, now a planked walkway, is held up by wooden pilings, some rising 20 feet from the ground.

The Dungeness River, normally a placid and shallow waterway, swelled to a torrent early today from heavy rains, overflowing its normal banks in many areas and reaching about foot below its official flood stage.

Trees undermined by the flooding also have been crashing down on the trestle.

Repair crews were called in to assess the situation, and late today the Clallam County Sheriff’s Office closed the entire bridge and its eastern and western approaches and in a press release warned of “a very hazardous situation”:

“The bridge at Railroad Bridge Park has been damaged due to high water in the Dungeness River and trees falling on it to the point where it is suspected that collapse [of the western trestle portion] is possible if not probable.

“Authorities have closed the [Olympic] Discovery Trail at either side of the bridge and are warning citizens to stay out of the area. Emergency personnel are on scene and monitoring the situation.”

The bridge is expected to be closed until at least next week, when a full assessment can be made of its safety and repairs made.

The bridge is the centerpiece of Railroad Bridge Park. The park is also home to the Dungeness River Audubon Center.

The walking and bike paths through the park and over the bridge are part of the Olympic Discovery Trail. The trail will eventually run from Port Townsend to the Pacific Coast, but for now it is primarily about 60 miles in and around Port Angeles and Sequim.

Walkers, horse riders and bikers using the trail will now need to detour around the Dungeness bridge area.