Engineers continue to study the abandoned trolley bridge over the Clackamas River, whose foundations appear to have shifted.
The owner, Union Pacific, says the bridge was inspected within the last year, as a part of talks to include it in a walking trail between Gladstone and Oregon City.
Union Pacific spokesman, Aaron Hunt says engineers have been working to get a better understanding of what caused the problem and how it might be fixed.
He says they're working with local property owners and state agencies to stage equipment near the foundations, "We're going to have some trucks with an arm attached to the truck where we can get some of our engineers in a little closer to the bridge without jeopardizing their saftey," said Hunt.
"We're not to the stage yet where we are reinforcing the bridge in anyway," he explained.
Hunt says the bridge has not moved again since shifting about four feet Thursday morning.
He says Union Pacific owns more than 20,000 bridges and culverts over 23 states, and a failure of this magnitude is rare.
A decision about what to do could take a while.
This story originally appeared on Oregon Public Broadcasting.