Crews have completed the most critical phase of removing bedrock that threatened barges along a crucial stretch of the drought-starved Mississippi River in southern Illinois.

The work by contractors hired by the U.S. Army Corps of Engineers has staved off the shipping industry's fears that the treacherous channel could close to traffic.

Using excavators and explosives, workers cleared 365 cubic yards of limestone and added two vital feet of depth to the channel near Thebes, Ill., about 130 miles south of St. Louis.

That phase of the work began last month and addressed the most pressing threat.

Maj. Gen. John Peabody, commander of the corps' Mississippi Valley division, said Saturday that "the work has deepened the channel enough to successfully maintain navigation though this critical reach of the river."