Sorrow continues to mount in Toronto as more and more information is released about the passengers of Wednesday morning's fateful Ukranian International Airlines flight from Tehran to Kiev.

We now know that multiple Toronto residents were aboard the plane, which crashed just minutes after taking off from Iran's Imam Khomeini International Airport with no survivors.

The cause of the crash has yet to be determined, though speculation is rampant in light of ongoing geopolitical tensions and Iran's refusal to release the plane's black box for further investigation.

Toronto devastated after Iran plane crash kills 63 Canadians https://t.co/PyFjuqCAwf #Toronto pic.twitter.com/18AKHnL7bf

— blogTO (@blogTO) January 8, 2020

Sixty-three Canadians in total were killed in the incident, along with 82 Iranians, 11 Ukrainians and 10 Swedes, among others.

Of those Canadians, four were said to have been University of Toronto students. The Toronto District School Board confirmed to reporters that "a number of TDSB students and their family members" were also aboard the plane.

The York Region District School Board similarly stated that some of its students were among the victims. At least five more Toronto residents are thought to have been lost in the tragedy, including a married couple, a teachers' union employee, and mother with her nine-year-old son.

Here's what's known about some of the Toronto victims of the Iran plane crash https://t.co/Q2pDuQ653a #Toronto pic.twitter.com/3JO485cqTA

— blogTO (@blogTO) January 8, 2020

Many around the world are on edge waiting to learn more about why the plane went down, and just hours after Iran launched a ballistic missile attack on Iraqi military bases containing U.S. soldiers.

In Toronto, where many of those aboard Flight 752 were thought to be headed after a stopover in Kiev, the focus is on comforting the families and friends of those who were killed.

"We are deeply saddened by the tragedy of Ukraine International Airlines Flight 752," wrote Toronto Mayor John Tory in a statement released Wednesday afternoon.

"We now know residents from Toronto were on this flight and have lost their lives — they were our friends, our neighbours, our classmates, our co-workers, and our loved ones."

We now know residents from Toronto were on Ukraine International Airlines Flight 752 and have lost their lives – they were our friends, our neighbours, our classmates, our co-workers, and our loved ones. pic.twitter.com/w5oiJp99yP

— John Tory (@JohnTory) January 8, 2020

Tory revealed that the Toronto sign in Nathan Phillips Square had been dimmed in commemoration of the victims, and that flags at multiple city landmarks would be lowered for nearly a week.

"In honour of those innocent lives lost including the many who called Toronto their home, flags at City Hall and East York, Etobicoke, Scarborough, North York, and York Civic Centres will be lowered from today until end of day Monday," wrote Tory.

"I hope every single resident of Toronto will join me in working alongside the communities and people impacted by this tragedy to provide support and comfort during this difficult time," he continued.

"That is what we do as Torontonians when tragedy strikes."