A construction barge working near part of the riverwalk expansion project sank in the Chicago River on Thursday morning.
The barge, near the LaSalle Street Bridge, began taking on water overnight, according to Chicago Department of Transportation spokesman Pete Scales.
The barge is out of the way of traffic and is not hampering boat traffic on the river, Scales said.
Walsh Construction, which owns the barge, has called in a marine salvage company to retrieve it, Scales said. The firm was awarded the contract to build three blocks of the project last November.
Salvage divers were called in but had not been seen as of 11:45 a.m.
The six block expansion project was unveiled in 2012 and includes a theme for each block of the riverwalk.