GLADSTONE, Ore. The Old Trolley Bridge is dangerously close to collapsing near High Rocks on the Clackamas River.
The bridge is about a mile up river from the confluence with the Willamette River.
Construction crews spotted the bridge piling tilting downriver Thursday morning and after a few hours, the top of the bridge had moved almost 4 feet, according to Lt. Robert Wurpes with the Clackamas County Sheriff s Office.
Authorities were urging boaters to avoid going near the bridge. Engineers were also on scene evaluating the situation.
The bridge is an abandoned remnant of a trolley line operated by the now-defunct Portland Traction Company that connected Oregon City with Portland.