FBI probes online threats against Orlando-bound flight

The FBI says it is trying to determine who made online threats involving three commercial airline flights, causing the evacuation of two and the diversion of another.

A Delta Airlines flight from Los Angeles to Orlando was diverted to Dallas/Fort Worth International Airport Sunday evening due to the threats.

There was more than one message posted on Twitter about a bomb on the planes, according to authorities. FBI spokeswoman Laura Eimiller said Monday that agents were investigating whether the threats came from the same person or from copycats.

Once the Orlando-bound plane landed in Texas, the 179 passengers and eight crewmembers aboard were evacuated. Investigators inspected the plane, but nothing harmful was found, an airport spokeswoman said.

"Somebody puts it up on twitter, now everybody knows a threat has been made," said Gary Kessler, homeland security professor at Embry-Riddle Aeronautical University.

Kessler said investigating the threat and tracking down who posted it could prove to be difficult.

"It doesn't matter how strong our security is, there is only so far you can go in doing an investigation," said Kessler.

Kalani Del Rae-Maher, a passenger on the plane, said there was concern among other passengers.

"We were sitting there holding each other's hands like, 'We have to get to Orlando.' This is not how today was supposed to go," said Rae-Maher.

The passengers of Flight 1061 boarded Flight 9812, which landed at Orlando International Airport late Sunday evening.

Two other planes were evacuated on arrival at Seattle-Tacoma International Airport due to the same threats. An airport spokesman said a JetBlue flight from Long Beach, California, and a regional SkyWest jet from Phoenix were the planes involved. The flights arrived late Sunday afternoon.

The incidents follow threats tweeted to two airlines that resulted in fighter jets escorting two flights into Atlanta's Hartsfield-Jackson International Airport on Saturday. Both planes landed safely.