Chopper7HD was first on the scene shortly before 6 a.m. as the Chicago Fire Department and the Chicago Police Department Marine Unit responded and deployed two divers.
A fire department helicopter also was in the air.
There were reports that crews were looking around an area on the east side of the bridge where they saw some clothing, but divers did not find anyone.
Eastbound Diversey was closed off to traffic at the Chicago River while the search was under way. All lanes are back open now.