Passengers aboard an American Airlines Boeing 737 MAX 8 were forced to evacuate after the aircraft aborted takeoff at Denver International Airport on Saturday due to a mechanical issue that triggered a fire and heavy smoke.

Flight 3023, which was bound for Miami, had 173 travelers and six crew members on board when the problem occurred during the takeoff roll. The Federal Aviation Administration (FAA) reported that the jet experienced a suspected landing gear malfunction, prompting an immediate halt to the takeoff.

Air traffic control audio captured the urgency of the moment. “Flight 3023, you got a lot of smoke. There was some flames,” a controller was heard saying, later adding, “You are actually on fire.”

Dramatic video taken at the scene showed dense smoke billowing from the aircraft’s left rear side as passengers evacuated using inflatable emergency slides. Emergency teams, including the Denver Fire Department, responded rapidly and extinguished the flames.

American Airlines later confirmed the incident stemmed from an issue with one of the tires during departure. “All passengers and crew exited the aircraft safely,” the airline said in a statement. “The plane has been taken out of service for a thorough inspection, and we appreciate our crew’s quick response and regret the inconvenience caused to our customers.”

The FAA stated it is conducting an investigation into the event. In the meantime, passengers were transported back to the terminal by bus and were expected to continue to Miami on a replacement aircraft.

Airport and airline officials reported that six individuals were evaluated for minor injuries—five on the runway and one later at the gate, who was transported to a hospital for further care.