A bridge that carries Interstate 43 over the Fox River has been closed indefinitely this week after drivers discovered that a support pier had "settled" over 2 feet.

The pavement has a deep dip, approximately 400 feet long and 20 inches deep, going across four lanes of interstate. The issue was reported to police before sunrise on Sept. 25, according to USA Today.

"Our No. 1 priority is public safety," Gov. Scott Walker said during an afternoon press conference. "We will fix this bridge."

The 33-year-old bridge is reportedly "not in danger" of collapsing, according to state Transportation Secretary Mark Gottlieb.

Wisconsin Department of Transportation officials said that they're not sure how long the bridge will be closed, if it must be replaced or how much repairs will cost. More will be revealed once an investigation is completed.

"It could be months. It could be a year," said spokesman Kim Rudat, according to USA Today. "This is a surprise. It's a significant event."

The pier likely settled at around 9:45 p.m. on Sept. 24 and 5 a.m. on Sept. 25.

Work was completed on the bridge earlier this year as part of a $17 million project to improve 3.5 miles of I-43, including the bridge.

The Leo Frigo bridge carries over 40,000 vehicles a day, and opened on Oct. 4, 1980. It cost $32 million and four years of construction.

Related Articles:

Curiosity Rover Finds Water on Mars

Alaska Dinosaur Tracks: Thousands of Footprints Found Near Yukon River

2014 Audi A6 TDI Commercial Starring Claire Danes Goes Viral (VIDEO)

State Fair of Texas Update: 2015 Ford F-Series Super Duty Lineup Debuts

GM CEO Dan Akerson Feels a Woman Will Run One of The Detroit 3 Soon

See Now: OnePlus 6: How Different Will It Be From OnePlus 5?