Passengers slid down an emergency slide of a smoking jet at Denver’s airport on Saturday due to a possible problem with the plane’s landing gear, authorities said.

A small fire in the brake system just ahead of the jet’s takeoff prompted the evacuation of 173 passengers and six crew members, the authorities said.

Passengers on an American Airlines flight departing from Denver International Airport Saturday were evacuated after a “possible landing gear incident,” according to the Federal Aviation Administration.