Twenty one passengers - including three children - on an Air Canada flight from China have been taken to a Calgary hospital after turbulence caused multiple injuries Wednesday. Flight 88 was en route to Toronto when the airplane encountered violent turbulence and was forced to stop in Calgary to treat the injured. Fifteen ambulances were dispatched to the scene as Emergency Medical Services enacted its mass casualty protocol. Passengers were taken through the terminal on stretchers and wheelchairs to waiting ambulances, but EMS officials said all of the injuries were non-life-threatening. Passengers who were not injured described a frightening scene during the turbulence. An artist who goes by the name Zarum said the turbulence began when the plane was roughly over Dawson City. "I was laying flat in a business class seat, I had my seatbelt on and suddenly I saw the passenger in front of me go flying up in the air, literally to the ceiling, and then hitting the ground again," Zarum said. "And then passengers started screaming and objects started flying. It last maybe half an hour." One passenger, Bing Feng, said she was thinking about her parents and siblings. "I heard lots of people screaming, like what you would hear on a roller-coaster," she said. "When you are in the situation, of course [you fear the worst]. You saw all the oxygen masks drop." The Transportation Safety Board said an investigation will be conducted focusing on the digital flight recorder and the cockpit voice recorder, as well as by interviewing the crew. John Lee, western regional manager for the safety board, said it hopes to determine "how big a bounce" the plane encountered and whether the turbulence was a surprise event or occurred over a period of time during the flight. Air Canada said in a statement it was making arrangements to accommodate all passengers, including those moving on to Toronto. "A full investigation of the incident is being undertaken," the statement said. The airline said the passenger list indicated there were 332 passengers and 19 crew aboard the Boeing 777-300ER.