In a post called “My Lucky Day,” Antonis Mavropoulos shared an image of what appears to be his boarding pass and says he arrived at his gate just after boarding had finished on Sunday morning.
“When I arrived, boarding was closed and I watched the last passengers in (the) tunnel go in. I screamed to put me in but they didn’t allow it,” he wrote.
The flight crashed six minutes after takeoff, killing all 157 people on board.
Mavropoulos says he was transferred to the next flight to Nairobi but was later told he was unable to board because security wanted to talk with him after discovering the plane had lost contact.
A security staff member “told me gently not to protest and say thank you to God, because I am the only passenger who did not enter the flight,” Mavropoulos wrote.
Mavropoulos wrote that he texted friends in Nairobi trying to get news of the plane, before eventually receiving a message from a friend in Greece confirming the news.
“I collapsed because then I realized how lucky I was,” he wrote.
Ethiopian Airlines said passengers from at least 35 countries were on the flight.
The crash has led to questions about Boeing’s new 737 MAX 8 jet, which was also involved in the Lion Air crash that killed 189 people last October.
“At this point, based on the information available, we do not have any basis to issue new guidance to operators,” Charlie Miller, Boeing’s vice president of communications, said in a statement.