An ice cooler found in a trash bin triggered a 90-minute evacuation of the Terminal 4 ticket counter at Phoenix Sky Harbor International Airport Monday.
Police say a passenger apparently threw the cooler into the trash after discovering the item couldn't be carried on a plane.
An airport employee who saw the cooler thrown away contacted police, and officers gathered their bomb-sniffing dogs.
"When the dog was brought over, the dog got an alert on the item and that caused us to close a portion of the airport," said Phoenix Police Sgt. Trent Crump.
People were moved out of the ticket counter area at 11:30 a.m. while officers checked out the cooler.
When police gave the order to evacuate, it was chaos, a traveler told us.
"They were just trying to get everyone out as soon as possible. There was shoving. I almost got knocked over by some woman," said Jacob. "I didn't know what it was. I didn't know if it was a weapon or just some sort of suspect. I hear many things, like it could be a bomb or something."
A bomb squad determined the object was harmless. Police contacted the person who dropped it in the trash. That person claimed they didn't want to take it on the plane anymore.
Some ice packs were inside the cooler, which may have caused the dog to react.
"Some of those contain some of the nitrous compounds that we use to train the dogs, and so very easily could have been something along those lines that the dog was picking up," said Crump.
The ticket counter reopened at 1 p.m. and operations returned to normal.
"Despite the fact that it can cause some disruption, we always ask that people report any suspicious items or any suspicious activity," said airport spokesperson Deborah Ostreicher.
US Airways, Southwest Airlines, Aeromexico, Air Canada, AirTran, British Airways and WestJet are served in Terminal 4.
There were no flight delays because of this, but because the ticket counters were closed, the airport says some travelers did miss their flights.
The trash cans in the terminal are actually reinforced bomb-resistant trash cans, which is why police didn't have to clear the whole terminal.
The Associated Press contributed to this report.