By Kevin Murphy
(Reuters) - A major freeway bridge near Green Bay, Wisconsin, was closed indefinitely on Thursday after it suddenly developed a dip that was described by one policeman as like a roller coaster.
A 400-foot span of the Leo Frigo Memorial Bridge that carries Interstate 43 traffic over the Fox River near Green Bay, Wisconsin was left with a rippled surface. "It's something akin to a roller coaster, actually," Lieutenant Karl Ackermann of the Green Bay Police Department said on Thursday.
One of the bridge piers settled, causing the sag, Wisconsin Department of Transportation officials said in a statement.
The problem was reported by a motorist early on Wednesday morning before the rush hour, Ackerman said. Police closed the bridge for safety reasons and no accidents or injuries were reported, he said.
The bridge is commonly used by large trucks and other traffic as a bypass around downtown Green Bay, Ackermann said, and carries about 40,000 vehicles per day.
Built in 1980, the bridge will be closed for an indefinite period to determine the cause of the problem and whether other piers have also settled, officials said. It was last inspected in 2012 and was not among 60 bridges in the state listed as deficient.
The surface of the Wisconsin bridge after the settling looks somewhat similar to the freeway bridges in San Francisco after the 1989 earthquake.
In May, a 160-foot (48-meter) section of the Interstate 5 bridge over the Skagit River about 55 miles north of Seattle collapsed after being struck by a truck carrying an oversize load. Two vehicles behind the truck plunged into the frigid waters below and three people were plucked from the water with minor injuries.
In 2007, an Interstate 35 bridge in Minneapolis collapsed, killing 13 people and injuring 145. A design flaw was blamed for that collapse.
In 2002, 14 people died when a barge plowed into an Interstate 40 bridge over the Arkansas River near Webbers Falls, Oklahoma, and a section of it collapsed.
(Reporting By Kevin Murphy; Editing by Tim Dobbyn)