A 41-year-old man struck and killed by a plane taking off at Denver International Airport was intending to end his own life when he scaled a remote fence and walked onto a runway, authorities said Tuesday. Sterling McLaren, chief medical examiner for the city and county of Denver, said no note was recovered and officials determined the cause of death to be suicide based on their post-mortem examination. She did not provide further details. The collision involving the Frontier Airlines plane sparked an engine fire that forced passengers to evacuate. A black-and-white video released by the airport shows, from a distance, a tiny figure walking toward the runway with arms swaying. The person crosses onto the runway at a slight angle and seconds later the plane is seen speeding past. It appears to strike the person with its right engine, which bursts into flame upon impact. —- EDITOR’S NOTE — This story includes discussion of suicide.…