(Above) On the Chicago River near the LaSalle Street Bridge, a white marine demarcation barrier marks where a construction barge sank Thursday morning. (Click on images to view larger versions.)

July 10, 2014 – A floating construction barge took on water early Thursday morning and slowly sunk to the bottom of the Chicago River.

There were no injuries. It is unknown why exactly the barge sank or what equipment was lost. It is safe to say that every barge is used to support heavy equipment.

At the scene, workers say the barge, 50 feet long by 20 feet wide, started sinking at about 4 a.m. The barge was just east of the LaSalle Street Bridge.

Air will be pumped into the barge to help raise it, a process that could take a few days.

(Above) What the barge would have looked like floating on the river. This construction barge was in front of Marina City on June 5.

The incident does not appear to be slowing construction of the Chicago Riverwalk. The Chicago Department of Transportation announced on Thursday that the State Street Bridge would be closed to traffic next week so that caissons can be installed beneath the bridge.

The bridge will close to all traffic for seven days starting on Monday, July 14 at 6 a.m., and re-open at an unspecified time the following Monday.

(Above) How traffic will detour when the State Street Bridge is not an option. Cars and trucks will use LaSalle and Clark. Bicycles will use Dearborn.

Over the next week, construction workers will continue pumping water out of the space between the existing Riverwalk and the new steel sheet pile that forms the new river wall, then back-filling the space with crushed stones.

Other remaining work includes pumping concrete into a caisson west of State Street, installing walers to help support the river wall between State and LaSalle Streets, and installing new drainage structures.

• Previous story: Riverwalk foundation work returning to Clark Street
• More photos: Riverwalk construction