At least one minor injury to a passenger has been reported and all those onboard the plane are being evaluated, which is standard procedure following an evacuation.
The incident happened at about 11:19 p.m. MT Friday when Frontier Flight 4345 reported striking a pedestrian during takeoff, according to a statement from Denver International Airport. There were 231 souls on board.
Passengers evacuated the aircraft on the runway and were bused to terminals by emergency crews.
Pilots reported an engine fire and smoke inside the aircraft following the incident, according to air traffic control audio obtained by ABC News.
"Tower, Frontier 4345, we're stopping on the runway. Uh, we just hit somebody... we have an engine fire," the pilot is heard on the audio from ATC.
When asked how many people were aboard, the pilot responded, "We have 231 souls on board... There was an individual walking across the runway."
Moments later, the pilot reported worsening conditions and the need to evacuate.
"We've got smoke on the aircraft, we're gonna evacuate on the runway," the pilot said.
The Denver fire Department responded to the scene and extinguished the fire.
Authorities have not released additional information about the person on the runway or the circumstances that led to the incident.
"Emergency response and investigation are ongoing. The NTSB has been notified. Runway 17L will remain closed while the investigation is conducted," the statement from Denver International Airport read.
The Denver Police Department is assisting with an investigation into the incident but said they do not have any further information to provide as it is an active investigation.
ABC News contributed to this report.
This is a developing story. More details will be added as more information becomes available.