Florida expert flies to Chicago to help catch alligator An expert from Florida has been summoned to Chicago to help authorities catch an elusive alligator in a public lagoon

CHICAGO -- An expert from Florida has been summoned to Chicago to help authorities catch an elusive alligator in a public lagoon.

Sections of Humboldt Park are closed Monday while the search continues for the gator, which is at least 4 feet long. Investigators confirmed the sighting last week but don't know what's it doing in Chicago.

Frank Robb of St. Augustine, Florida, arrived on Sunday and immediately began assessing the park and lagoon.

Chicago Animal Care and Control says Robb recommended that certain areas be closed to the public so the alligator isn't spooked. Photos of the gator started showing up on social media about a week ago.