North Dakota, US: Sinkhole closes Fargo overpass

North Dakota, US: Sinkhole closes Fargo overpass

© Dave Wallis / The Forum
The Seventh Avenue North bridge over Interstate 29 in Fargo was closed to traffic after the asphalt road surface caved in because of a sinkhole that opened up Sunday

A bridge over Interstate 29 in north Fargo, slated to be replaced next year, is still sound after a sinkhole was discovered this past weekend near its base, officials say.

Traffic is being detoured away from the Seventh Avenue North overpass because of the sinkhole, which measures about 2 feet deep and 3 feet wide, said Lee Anderson, Fargo Public Works maintenance supervisor.

Jamie Olson with the North Dakota Department of Transportation said Monday that engineers found the sinkhole caused no problems for the 45-year-old bridge.

"There are no issues with the structure of the bridge," Olson said.

NDDOT plans to fully reconstruct the two-lane overpass in 2012, widening it to include an enclosed pedestrian walkway.

The sinkhole was first reported at about 11 "There are no issues with the structure of the bridge," Olson said.

NDDOT plans to fully reconstruct the two-lane overpass in 2012, widening it to include an enclosed pedestrian walkway.

The sinkhole was first reported at about 11 a.m. Sunday in the eastbound lane of Seventh Avenue where the bridge deck meets the base on the east side of the overpass, Anderson said.

The base material under the pavement had washed away, leaving a void beneath it, Anderson said, adding that the area's wet weather probably contributed to the erosion.

"It's not uncommon in storm sewers and stuff like that, but for there, it's a little bit uncommon," he said. "And this didn't happen overnight. This has been going on for a while, the way it seems."

NDDOT will decide what repairs are needed, Anderson said.

The overpass is frequently used by trucks going to Fargo's landfill and industrial park. The landfill has been "extremely busy" the past two weeks as contractors and residents cleaned up from a Memorial Day storm that packed winds of more than 70 mph and downed trees in the metro area, Anderson said.