Investigators say Hye Min Choi, 19, who also goes by Joseph, checked in at O’Hare International Airport in Chicago on Saturday.
He was scheduled to take a United flight to PTI in Greensboro. He never made it.
United Airlines told police that Choi did not book another flight through them.
Police say his mother picked up his luggage at PTI airport in Greensboro Saturday night.
A family friend says Choi spoke to his father a couple hours before his scheduled flight.
“I think he had mentioned that he was hungry to his dad, and that was about it. He just mentioned that he would see him on the other side,” said Hunmin “David” Yijae.
Choi is a student at the University of Illinois at Urbana-Champaign majoring in mechanical engineering.
A school administrator confirmed that Choi attended Northwest Guilford High School, where he graduated fourth in his class.
Ralph Kitley, the principal at Northwest Guilford High School said, "Joseph was an excellent student at Northwest High who was always respectful to school staff and his peers. Our hearts go out to his family during this difficult time, and we will keep them in our thoughts until he is found.”
Police said Choi could be a runaway.
“The young man was apparently having some problems in school. We have some leads on where he may be. It appears he may or may not have wanted to go home,” said Chicago Police Superintendent Garry McCarthy.
Choi is described as a 5’6″, 100 pounds, Asian Pacific Islander, with brown eyes, black hair and a medium complexion. He has a scar on his right eyelid.