Officials closed a major Mississippi River bridge between Tennessee and Arkansas for nine hours Aug. 27 after a pier under a small approach span settled 3.5 inches overnight in a construction zone.
An inspector noticed the problem on the I-40 approach just after rush hour Monday morning.
After the discovery, both spans were closed and traffic was diverted to the nearby I-55 bridge.
The approach span for the I-40 bridge was still supported by other piers, so the most motorists might have noticed would have been a slight dip, said Arkansas Highway and Transportation Department spokesman Randy Ort.
Ort said the problem was likely caused by additional, longer pilings being driven to improve the bridge's stability. While crews worked beneath one half of the bridge, the other half was carrying 35,600 vehicles daily.
"The settling was in the columns still under traffic, due to the construction adjacent to it," Ort said.
River bridges have been under scrutiny across the country since the Aug. 1 collapse of the I-35W bridge.
Workers have been improving bridges along I-40 to make them safer in case of earthquakes.
Tennessee Department of Transportation spokeswoman Pamela Marshall said she's not sure that the Minneapolis bridge collapse played a role in the decision to close the bridge.
"It is a bold stance, considering how busy these bridges are, just to shut them down," she said. "It is at the front of everybody's mind. Let's learn from other situations."