At least a third of the 176 passengers killed in the Boeing 737 crash in Iran were Canadians, likely taking advantage of cheap flights home to Toronto, which has one of the world’s largest Iranian diasporas.

Sixty-three Canadians were killed on the Boeing 737-800 jet that crashed early Wednesday in Sabashahr, near the Iranian capital. They were among 167 passengers and nine crew who lost their lives, including 82 Iranians, and 11 Ukrainians, according to Ukraine’s foreign ministry.

Canada’s 2016 census shows 210,405 people identifying as at least part Iranian and their neighborhood in north Toronto is often referred to as “Tehranto” by the Persian community.

“I’ve had family take the Tehran to Toronto route via Kiev in the past year,” said Mahsa Alimardani, an Iranian-Canadian and University of Toronto graduate.

Canada’s Foreign Affairs Minister Francois-Philippe Champagne expressed condolences in a tweet. “Our hearts are with the loved ones of the victims, including many Canadians,” he said. “I have been in touch with the government of Ukraine. We will continue to keep Canadians informed as the situation evolves.”

After the crash, Global Affairs Canada issued an advisory warning Canadians against traveling to Iran, citing “threat of terrorism and the risk of arbitrary detention.” The statement didn’t mention the Boeing 737 crash.

Iran’s Disaster Mitigation and Management Organization said early assessments indicate the cause was a technical issue; the transport ministry initially suggested an engine fire was to blame. The timing of the crash, which coincided with Iranian strikes against U.S. bases in Iraq, sparked speculation the jet could have been struck by a stray missile, or been downed by a terrorist attack.