TRENTON, Canada 

Canadian Prime Minister Justin Trudeau said Wednesday it was a “somber day” after a plane leaving from an airport in Iran crashed shortly after takeoff, killing all 176 people on board, including 63 Canadians.

On video carried live by Canadian news services, Trudeau addressed the tragedy.

“Canadians across the country were shocked and saddened,” he said. “They had so much potential, so much life ahead of them.”

Answering reporters’ questions, Trudeau said while it was “too early to speculate on the cause” of the crash, he could not rule out that the plane had been shot down.

He said the crash would be “thoroughly investigated.”

“Canadians have questions and deserve answers,” he said, adding Canadian Foreign Minister Francois-Philippe Champagne will talk to his Iranian counterpart and stress the need for an extensive investigation.

Of the 176 on board the Boeing 737-800, 138 were flying to the Ukrainian capital of Kyiv to make a connecting flight to Canada. The victims included 63 Canadians, 82 Iranians, 11 Ukrainians, 10 Swedes, four Afghans, three Germans and three British nationals.

The Ukraine International Airlines flight used a plane that had been built in 2016, was inspected on Monday and had a “very, very good safety record,” said aviation expert John Cox, chief executive director of Safety Operating Systems based in Washington, D.C.

While Trudeau wanted Iran’s help in determining the reason for the crash, he condemned the Iranian missile strikes Tuesday on Iraq where both American and Canadian troops were stationed. No one was killed in the attack.

“They are all safe,” he said.

Nevertheless, Canada is temporarily moving many of its troops out of Iraq.

The Iranian attack came after the U.S. killed Iran’s top general Qassem Soleimani last week.

In the wake of Wednesday’s crash, Air Canada, along with many commercial airlines, is rerouting flight paths to avoid the area.