After American Airlines Flight 1102 landed safely shortly before 2 p.m. EST and was evacuated, the MD-Super 80 taxied to a holding ramp in the middle of the airfield, where it remained for several hours.
The plane was about to complete a flight from Chicago's O'Hare International Airport to Indianapolis when an attendant walking down an aisle noticed a strange object with a string on it, Rosebrough said. The object was on the floor near the rear of the plane.
"As she pulled the string, there was an unknown object which was attached to it," he said.
Authorities offered no details on whether the object was in the plane's seating area, and did not say who left it there.
The attendant contacted the pilots, and the device was taken to the back of the plane. The pilot requested an emergency landing. Police, fire officials, and a hazardous materials team were on the ground waiting for the plane.
The passengers and crew members used a slide to evacuate because the stairs brought to the plane did not fit. The passengers were taken on a shuttle to the airport's international terminal, where they were questioned as a group by investigators from the FBI and Transportation Safety Administration, Rosebrough said.
Within about three hours, all of the passengers had been released.
Mary Frances Fagan, an American Airlines spokeswoman, said the plane had been scheduled to make a return flight from Indianapolis to Chicago later in the afternoon.
The plane's first flight of the day was from Boston's Logan International Airport to O'Hare.
