Despite the winter weather, crews had three boats out in the canal for six hours, with divers in the water. They were trying to attach lines from a tow truck to something under the water at one point.
Stacy Peterson, 23, disappeared at the end of October. Her husband, Drew, a former Bolingbrook police sergeant, is considered a suspect in the case, which has been labeled a possible homicide.
Illinois State Police are leading the investigation due to the former cop's ties to the city. They were also leading Wednesday's search of the canal.
The Illinois State Police will not reveal exactly what led them to this body of water. But in the Lockport and Romeoville area, the canal is a well-known dumping ground. The search began at 8 a.m. Wednesday. They did not find the body of Stacy Peterson.
Several tow trucks were standing by at the site but came up empty. The Illinois State Police would only say the search in the Chicago sanitary and ship canal was triggered by their investigation. And investigators will not say whether a tip about the whereabouts of a body led them to the canal.
There were several government agencies and private companies that assisted with the recovery of some debris, including the U.S. Coast Guard and the Department of Defense.
Authorities will not say whether they plan to return to search the canal further.
On Wednesday, Stacy's family released a recording of the last voicemail she left her father on the family's Web site: www.findstacypeterson.com
Drew has denied involvement in Stacy's disappearance and in the 2004 death of his third wife, Kathleen Savio, which is now under review. Officials believe it may have been a homicide staged to look like a drowning.
Drew also faces allegations of police misconduct related to his time at the Bolingbrook Police Department.
On Tuesday, officials served a second search warrant at the Peterson home that dealt with items in two vehicles - a GMC Yukon Denali and Pontiac Coup.
"It expands the scope of the initial search warrant regarding items in his vehicles," said Charles Pelkie, a spokesman for the Will County state's attorney's office. He declined to elaborate, including what items police found or were searching for.
Peterson's attorney said he believes the warrant was a response to a motion he filed to get those vehicles back.