The Canadian government has not ruled a variety of possible causes for the crash of a plane carrying 63 Canadians.
But according to Prime Minister Justin Trudeau, evidence from multiple sources suggests that the Ukraine International Airlines jet was brought down by an unintentional Iranian missile strike.
Speaking to reporters today, Trudeau refused to convey any fault until a "credible investigation" is completed.
"I think it is too soon to be drawing conclusions or assigning blame in any proportions," the prime minister said.
But he left no doubt that a surface-to-air missile likely explains the tragedy.
The New York Times has obtained exclusive video showing the moment when the plane was hit.
All 176 passengers and crew members died.
There were 82 Iranians, 11 Ukrainians, 10 Swedes, four Afghans, three Germans, and three Britons on the doomed flight. And 138 of the passengers planned to take a connecting flight from Kyiv to Canada.
"My first thought is for the families, the families we have been getting to know over these past 24 hours," Trudeau said. "They are already going through a terrible, terrible grieving process."
He acknowledged that reports of a missile attack is compounding their suffering.
"The news will undoubtedly come as a further shock to the families who are already grieving in the face of this unspeakable tragedy," Trudeau said.
The Iranian Students' News Agency video below appears to show the plane on fire before crashing to the ground.
Pieces of the aircraft are spread over a large geographic area, suggesting that parts may have fallen off while it was still in the air.
U.S. officials have already told the media that the plane was shot down by Iran.
This came after intelligence officials detected signals of two missile launches two minutes after the plane departed from Tehran's airport.
Before the plane crashed, Iranian military forces had launched missile attacks at two military bases in Iraq with U.S. forces. Canadian troops were stationed at one of those bases, in Erbil.
These missiles were launched in response to an American drone strike on January 3 that killed senior Iranian general Qassem Soleimani in Baghdad.
Meanwhile in Metro Vancouver, people are mourning the loss of 12 local residents.
Iranian state television reported on January 11 (Iran time) that the Ukraine International Airlines jet was unintentionally shot down. The network cited a military statement.
On January 10, Foreign Affairs Minister François-Philippe Champagne said that 57 of the passengers were Canadian, not 63 as initially stated by Justin Trudeau.