A complete sweep of an American Airlines plane grounded in Austin, Texas failed to turn up anything suspicious, airport authorities said Friday afternoon.
American Airlines flight 2486 was scheduled to depart Austin for Chicago's O'Hare International Airport but was grounded after a threatening note was found in one of the plane's bathrooms,Airport spokesman Jason Zielinski said.
The note was found by a passenger, who reported it to the flight crew. The flight attendant notified the pilot, who informed the tower.
The plane never took off and was instead emptied and parked on the tarmac. The 129 passengers were rescreened and interviewed in Austin Bergstrom International Airport's South Terminal. Authorities conceded that it's possible the note was left by someone on an earlier flight.
All of the baggage on the plane was removed and checked by bomb-sniffing dogs from the Austin Police Department.
"The only thing that suggested a bomb threat was the note that was found in the restroom," Zielinski said.
The airport was not shut down and other flights were operating normally.
"We take every single incident as seriously as the next," Transportation Security Administration spokeswoman Andrea McCauley told Austin NBC affiliate KXAN-TV. "We are expected to apply our full force of resources to each and every incident as a part of our due diligence in the situation."
Austin police at the FBI have taken over the investigation and are processing the plane as a crime scene. If the FBI can determine who left the note, law enforcement could pursue civil and criminal penalties.
Passengers boarded another plane about four hours after the incident began and landed in Chicago at about 8:30 p.m.