Passengers had to evacuate a Southwest flight in Houston on Friday night when passengers and crew noticed smoke and a strange smell.
The Memphis-bound plane had just boarded when a "smoke smell was identified in the cabin," a Southwest spokeswoman said.
Passenger Adam Clemons said he detected smoke and a bad chemical smell from his seat near the back of flight 397.
Clemons, who is a producer for NBC Memphis station WMC, said he saw the captain head to the plane's rear to investigate the cause and heard him say, "this is not good."
After the captain checked on the smoke "everyone went full freak out," Clemons said.
The captain determined the plane needed to be inspected and the flight crew told the passengers they needed to exit the plane, which was still attached to the gate, the airline spokeswoman said.
"People were trying to get their bags and the chemical smell was so bad," Clemons said.
The plane was taken out of service for further inspection and the 81 passengers on board were put on a different aircraft, which arrived in Memphis with about a two-hour delay, according to the airline.