They were in the Covered Bridge Canyon area next to US Highway 6. The girls were in the area to take pictures of the fall colors, but that's when a train came by.
The girls were walking near the tracks when two trains coming from opposite directions hit them.
Their classmates wore their Sunday best to school October 15 to pay tribute to the girls' memory.
Friends also took to a Facebook page to remember the girls. Alicia Burrell wrote, "We're there in spirit! Even from hundreds of miles away, these amazing angels have affected the lives of others! I'm SO happy to see everyone supporting them and honoring the brilliant light they share with the world! They are making a difference!"
Emma Nichole Hilton wrote on Facebook page, "Tomorrow guys!! Don't forget!! October 15. The day we lost some angels?"
The Facebook post was shared over and over. "My daughter just told me that they were dressing up at the middle school," said Jennifer Pollard from Spanish Fork.
Half of the student body at the junior high and high school wore their Sunday best to remember.
"I think it just shows the unity in our valley and among the youth, they probably know it could have been any one of them," said Claudia MaCnaughtan from the Spanish Fork area.