Dutch passenger tweeted "If the plane disappears, this is what it looks like."
A picture of what is believed to be MH 17 was apparently posted by a Dutch passenger of the Malaysian flight shot down in Ukraine on Thursday.
In a Facebook post, Cor Pan, who was said to be going on a beach holiday to Malaysia, added a caption that roughly translates as, "if the plane disappears, this is what it looks like."
The photo is tagged "near Schiphol airport" and appears to have been taken from the gate as passengers waited to board in Amsterdam.
The joke, referencing the Malaysia Airlines MH 370 flight that disappeared in March, drew many amused responses.
But hours later, when news broke about a Malaysia Airlines plane traveling from Amsterdam to Kuala Lumpur has been shot down, friends started showing concern.
Late on Thursday his picture had been shared more than 10,000 times on Facebook.
The post is also viral on twitter, a chilling twist to the tragedy. Nearly 300 passengers and crew members died after the plane was shot down by what US officials say was a surface-to-air missile.
"So sad," said a tweet. "So erie (sic). So sad. So uncalled for," another post said.
Cor had earlier put up pictures of tropical beaches on his Facebook page, saying: "A few more days to wait yet..."
Another tweet claimed that the plane made its first trip exactly 17 years ago on the same day that it crashed - 17 July.
"Haunting: Malaysia Airlines Boeing 777, Reg 9M-MRD, made 1st flight on 7-17-97. It met its end 17 years later, to the day -aviation official," tweeted CJ Chivers.