Engineering experts worked through the weekend to investigate why a major bridge in Green Bay, Wis., began to sag last week, prompting its indefinite closure.On Sunday, crews finished placing movement sensors on three of the Leo Frigo Memorial Bridge’s piers, or support pillars, including pier 22, state Department of Transportation spokesman Mark Kantola told the Los Angeles Times.
It was pier 22 that settled Wednesday morning, causing a 400-foot span of roadway to visibly dip and prompting motorists to call 911. The Interstate 43 bridge’s contours posed an immediate hazard and had the potential to send drivers airborne, according to another Department of Transportation spokesman, Kim Rudat.
Installing the network of sensors, which sound an alarm if any movement is detected, clears the way for investigators to safely examine pier 22, its neighboring piers and the bridge’s underside, Kantola said.
Before Sunday, investigators had tested the soil underneath other sections of the bridge, trying to ascertain the composition of the earth and looking for clues as to why the ground may have settled, Kantola said.