The Wisconsin Department of Transportation said Thursday that corrosion caused a bridge piling to buckle, causing a significant dip in a Green Bay bridge.
The DOT said in a news conference that steel pilings under Pier 22 of the Leo Frigo Bridge, formerly known as the Tower Drive Bridge, corroded and buckled, causing the concrete bridge pier to sink.
The pilings are long steel rods that extend deep into the ground, supporting the footing of the bridge piers.
Officials said the piers themselves are in good condition and the overall structure of the bridge is sound. However, inspectors found that three neighboring piers are showing similar signs of corrosion, but to a lesser extent than Pier 22.
The bridge support, which is in an area that was formerly a wetland, sank about two feet on Sept. 25, causing the bridge to be closed indefinitely
DOT spokesman Kim Rudat said now that engineers understand what happened, they can start working on how it will be fixed.
"I mean, it took some detective work to reveal what happened and why it happened and how it happened, so we feel confident enough that as we finish our investigation, we already are developing fixes for it,' Rudat said. "We're going to fix it as quickly as we can and as safely as we can."