A portion of McNamara terminal at Detroit Metro Airport was evacuated briefly Tuesday because of a suspicious situation involving a piece of cargo.
TSA said a K9 alerted authorities to something abnormal during a routine inspection.
As a precaution, passengers at gates A20 to A38 were moved during the investigation.
The piece of cargo was x-rayed and cleared. Passengers were allowed back into the terminal area just before noon.
Planes were still allowed to take off and land during the evacuation.
TSA and the airport wouldn't comment on details of what they were investigating.