The 800-capacity auditorium at Warmbier's high school in the Cincinnati suburb of Wyoming was packed, as were overflow rooms set up to accommodate additional attendees.
Still more mourners lined roads in Wyoming, a small town of 8,000 residents, and in Cincinnati, where the 22-year-old was laid to rest. Some waved American flags while others held up signs with supportive messages as the funeral procession passed by.
Streets were adorned with blue and white ribbons tied to trees and light posts as a show of support.
Sentenced to hard labor early last year for stealing a political poster from a North Korean hotel, Warmbier was medically evacuated to the United States in a coma last week after nearly 18 months in captivity.
Doctors said the University of Virginia college student, who was on a tourist trip when arrested, had suffered severe brain damage while in North Korean captivity. He died Monday at a Cincinnati hospital.
Mourners carry the coffin of Otto Warmbier during his funeral in Wyoming, Massachusetts, USA, 22 June 2017. Source: EPA
President Donald Trump slammed Warmbier's detention and eventual death as "a total disgrace."
"This process has been a window into both evil, and love and good," one of Ohio's two US senators, Rob Portman, told reporters before the funeral, which was closed to the media.
"Today we're seeing the good, and the love that will be expressed through this outpouring of support for Otto and his family."
'Profound' loss
A long line of mourners formed in the early hours of the morning for Warmbier's funeral, held at the high school from which he graduated in 2013.
"This is our season finale. This is the end of one great show, but just the beginning to hundreds of new spin-offs," read a quote from Warmbier's graduation speech included in the program.
One of his former school counselors, who was attending the funeral, told CNN the community had been holding its collective breath while he was imprisoned in North Korea, "praying for a quick release, rallying around the Warmbiers as much as possible."
"He was going to set the world on fire, which is why this loss is so profound," Cynthia Meis said.
Fred and Cindy Warmbier watch as their son Otto, is placed in a hearse after his funeral, Thursday, June 22, 2017, in Wyoming, Ohio. Source: FR171481 AP
The service, which lasted a little less than an hour, concluded with Warmbier's casket being carried out as a bag-piper played the spiritual "Going Home."
'Appalling' treatment by North Korea
Warmbier's treatment by the reclusive North Korean regime sparked strong condemnation in Washington, and inflamed already high tensions stoked by Pyongyang's atomic tests and missile launches.
Trump denounced the "brutal regime" of Kim Jong-Un, and Portman called it "appalling."
"He never should have been detained in the first place," Portman said Thursday. "The North Koreans need to be held to account for that."
On Wednesday, Secretary of Defense Jim Mattis said that US patience with Pyongyang was running out.
"To see a young man go over there healthy and, (after) a minor act of mischief, come home dead basically... this goes beyond any kind of understanding of law and order, of humanity, of responsibility toward any human being," Mattis said.
