Ontario Provincial Police say the plane's pilot was Marko Misic, 20, of Toronto and the three passengers were Mohammed Shahnawaz Zia, 23, of Toronto, Wasay Rizwan, 27 of Toronto and Victoria Margaret Luk, 19, of Mississauga, Ont.
All four victims were pronounced dead at the scene.
The single-engine Cessna 172 had departed from the Waterloo Regional Airport at 6:10 p.m. Friday.
Police say it was supposed to fly to Toronto, then Niagara Falls, Ont., then back to Toronto.
But at some point during the flight, investigators say the four-seater plane encountered "unknown difficulties" and crashed into a cornfield in Mapleton, Ont.
The plane had been rented from the Waterloo-Wellington Flight Centre.
Witnesses say they spotted the plane weaving back and forth in the sky Friday evening about 50 kilometres northwest of Kitchener.
At first they thought it might be putting on a show, but seconds later it disappeared and Llori Nicholls, who was out with her husband walking their dog, says she heard it nose-dive into the ground.
The investigation is still ongoing but police say they don't believe weather was a factor because the skies were clear.
Also on HuffPost