CHICAGO (CBS) — A substance leaking from a piece of luggage prompted a hazardous materials response at Midway International Airport Monday morning.

As CBS 2’s Kris Habermehl reports, the leaking baggage was discovered sometime around 6 a.m. outside AirTran Gate A14 at the airport.

The Fire and Police departments immediately responded, and a Level 1 Hazmat response was called.

But the Fire Department quickly secured and called off the hazmat response, after finding that the leaking substance was “identifiable.” Authorities have not specified what it was.

Police continue to investigate.