A grieving father has been run over and killed during a 5,000-mile walk across America to raise awareness of homophobic bullying after his gay son committed suicide.
Joe Bell was struck by a truck in eastern Colorado on Wednesday evening as he walked along the shoulder of a highway.
The 48-year-old from Oregon began his marathon walk in April after the death of his 15-year-old son Jadin in January.
On the Joe's Walk for Change Facebook page, a post announced Mr Bell's death and paid tribute to the father who had been speaking at schools and clubs across the U.S. about homophobic bullying.
"We need to stop this bullying - it starts in our households, how we raise our children," Mr Bell said at the time.
"We need to educate our school systems on how to deal with it; they don't know how to deal with the problem."
He had been due to talk to a youth group in Hugo, Colorado, on the night he was killed.
A few hours before his death, Mr Bell posted a picture of a road sign on Facebook with the caption: "Making headway, one step at a time."
The organiser of the Facebook page later announced his death, saying: "I am very sad to have to announce that our friend Joe Bell was hit and struck by a semi while on his walk last night.
"He will continue his journey now with Jadin."
Mr Bell's son suffered brain damage after attempting to hang himself at a La Grande school on January 19.
He was kept on life support for a few days, before Mr Bell and Jadin's mother Lola Lathrop agreed to end treatment after doctors registered little brain activity.
The 15-year-old student had been the victim of relentless bullying in school and on social media sites because of his sexuality.
Following the death of Mr Bell, truck driver Kenneth Raven has been cited with careless driving resulting in death. Police believe he may have fallen asleep at the wheel.