The eight-day trip included a white-water rafting experience in North Carolina that would prove deadly.
Colin Evans told WBNS he shared a raft with Seitz that day at the U.S. National Whitewater Center, an outdoor recreational park in Charlotte that features a man-made white-water river ride.
"We went around three times. Everybody fell out. It was fun. We both fell out at the same spot both times. We helped each other back in."
But unlike her compatriots who fell into the water that day, Seitz would soon contract a deadly infection.
Days after returning home, Seitz would develop a headache and congestion, according to an North Carolina Health and Human Services investigation. She would soon be admitted to the hospital and suspected of having meningitis.
On June 19, the 18-year-old was dead.
Two days later, officials say, the Centers for Disease Control and Prevention confirmed the presence of Naegleria fowleri, commonly referred to as a "brain-eating amoeba."
A year after her death, Seitz's father has filed a lawsuit against the U.S. National Whitewater Center, claiming negligence and asking for $1 million in punitive damages.
A spokesman for the nonprofit organization that owns and operates the park said in an email that it does not publicly discuss matters related to litigation. The co-defendant named in the suit, Recreation Engineering and Planning, did not immediately respond to requests for comment.
As The Washington Post's Elahe Izadi wrote, Naegleria fowleri "resides in warm freshwater, hot springs and poorly maintained swimming pools."
Infection can occur when it enters the body through the nose. Of the 140 people known to have been infected in the United States from 1962 to 2016, four people have died, according the CDC.
James Seitz did not respond to a message for comment sent on Facebook. The plaintiff's lawyer said that the defendants have yet to respond to the suit.
The North Carolina Health and Human Services's investigation found that the amoeba was "present throughout the white-water feature."
After Seitz's death, the U.S. National Whitewater Center temporarily closed its white-water facilities. According to CBS News, the center's website said at the time that "the fast-water channels would be drained, dried and scrubbed to kill any vestiges of the amoeba."
The Whitewater Center is now required to be inspected and obtain an annual permit from the county health department, WSOC-TV reported.
Criminal defense attorney James Wyatt told news outlet WSOC-TV that an issue will be whether Lauren Seitz signed a release document.
"With a waiver, generally a judge will interpret the terms of the waiver and determine whether it bars the lawsuit," Wyatt said.
Speaking to ThisWeek Community News last year after his daughter's death, James Seitz said she "believed in the power of music and the arts to inspire all of us to take better care of the earth and each other."
The family started a memorial music fund in the teen's honor.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)