The incident caused extensive damage to the device, which is making it difficult to identify the specific model, Capt. Kevin Fletcher of the Louisville Metro Arson Bureau told WAVE, the NBC affiliate in Louisville. He said that at the moment he can only say the electronic device, which looks like a cellphone, is a Samsung.
Last month, the U.S. Consumer Product Safety Commission officially recalled the Samsung Galaxy Note 7 after reports of the batteries catching fire. A Samsung spokesperson told CNBC on Wednesday that there is "no evidence that this incident [on the Southwest airplane] is related to the new Note 7." The electronics-maker said it is working with the airline and authorities to recover the device and confirm the cause.
The owner of the device told The Verge that it was a replacement Galaxy Note 7.
Capt. Fletcher said, however, that while the carpet of the aircraft has been singed, there is very minor damage to the aircraft. The plane was ventilated by the response team, so there was no smoke when the arson bureau arrived, Fletcher said.
The Federal Aviation Administration said in a statement that "the crew of Southwest Airlines 944 reported smoke in the cabin while parked at a gate at Louisville International Airport at about 9:20 a.m. today." WAVE reported that the flight had been originally scheduled to depart at 9:30 a.m. ET. The flight appears to have been cancelled, according to Southwest's website.
Southwest said in a statement that a customer reported smoke coming out of a device.
The FAA said Airport Rescue and Fire Fighting responded and that it "will look into the source of the smoke."
A spokeswoman for the Louisville airport said a total of 75 people were on the plane at the time and that no slides were deployed during the evacuation.
— NBC News' Melanie Kucera and Jay Blackman, and CNBC's Jim Forkin contributed reporting.