Chicago Sanitary and Ship Canal.
That's the waterway where more than 2,000 gallons of toxin were dumped Wednesday as part of efforts to halt the spread of the invasive Asian carp.
Illinois environmental officials hoped to kill off any carp in the canal while the electrical barrier that's designed to keep them from the Great Lakes is turned off for maintenance.
Biologists from the Illinois Department of Natural Resources are monitoring the fish kill. Department spokesman Chris McCloud says more than a dozen boats will be used later in the day to begin cleanup operations.
Environmentalists fear the carp could starve out other fish and cause the collapse of the $7 billion-a-year Great Lakes fishing industry.
Fish and wildlife officials will poison a 6-mile stretch of water near Chicago on Wednesday in a last-ditch effort to keep one of the most dangerous invasive species of fish, the Asian carp, out of the Great Lakes.
The Asian carp, a voracious eater that has no predators and negligible worth as a commercial or sport fish, now dominates the Mississippi and Illinois rivers and their tributaries.
The fish has entered the Chicago Sanitary and Ship Canal - a man-made link between the Mississippi River system and the Great Lakes - and is knocking on the door of Lake Michigan. Once inside a Great Lake, the carp would have free rein in the world's largest freshwater ecosystem, imperiling the native fish of the lakes and a $7 billion fishing and recreation industry.
"We've got a chance to beat this thing, but we've got to do everything right," says Joel Brammeier, acting president of the Alliance for the Great Lakes, a conservation group.
The poisoning will kill an estimated 100 tons of fish, which will be removed by crane and hauled to a landfill
WZZM's Sarah Sell is in Illinois Thursday for more on this story. Tune in at Noon, 5:30 & 6pm.