A terrifying scene unfolded at Denver International Airport Saturday afternoon after an American Airlines flight preparing for departure caught fire, forcing more than 170 people to evacuate in panic via emergency slides.

Flight 2341, a Boeing 737 MAX 8 bound for Miami, was taxiing for takeoff around 2:45 p.m. local time when a mechanical failure involving its landing gear sparked a tire fire on the runway.

As thick black smoke billowed into the air, flight crew deployed emergency slides and 173 passengers and six crew members scrambled to evacuate. Several passengers described chaos on board, with some shouting and others rushing toward exits as the cabin filled with fumes.

Emergency crews from the Denver Fire Department responded swiftly, extinguishing the flames while passengers were being led away from the aircraft on the tarmac. Images and videos shared on social media showed dramatic scenes of people fleeing the plane.

According to airport officials and American Airlines, five people were treated at the scene, and one person was transported to a hospital with minor injuries.

The FAA has confirmed it is investigating what it initially called a “possible landing gear incident.” American Airlines later clarified the aircraft had experienced a maintenance issue involving a tire prior to takeoff, which may have triggered the fire.