Updated May 29 at 7:34 a.m. ET.
(CBS/AP) TORONTO - An Air Canada jet bound for Japan made an emergency landing in Toronto Monday afternoon after an engine shut down shortly after takeoff from Pearson International Airport. No injuries were reported.
Police believe that chunks of metal that fell on cars near Pearson International Airport came from the Air Canada Boeing 777 jetliner. Investigators know of four vehicles that were hit by pieces of metal about the size of a cellphone, said Peel regional police Constable George Tudos.
Witnesses reported seeing a plane with smoke coming from one of its engines shortly before police got calls about the falling debris, Tudos said.
"As it (the plane) was traveling away from Pearson we had other complaints stating that debris, consisting of metal objects, was falling from the sky," he said.
"It's just really, really strange, not something I expected to happen today, having airplane debris falling through my windshield," witness Jonathan Bergen said.
Tudos said there were no injuries from the falling debris and stressed that police can't positively say the debris came from the Air Canada plane.
Air Canada spokesman Peter Fitzpatrick said the plane's crew requested an emergency landing shortly after takeoff when one of its two engines failed. The plane returned to Pearson and landed normally using one engine. Fitzpatrick said the cause of the engine shutdown was not immediately known.
Fitzpatrick said there were no injuries among the 318 passengers and 16 crew members aboard Flight AC001 bound for Tokyo's Narita airport.
Jason Flick, a businessman who was on the flight, told CBS News that the plane came in "very fast. I mean at least twice the normal speed. "
"They told us the engine had overheated and they were running on one engine. They told us they were going to have to dump fuel ... then their only concern was the brakes. They brought a big fan to cool them off ... our biggest concern after we landed was that all 300 of us were very hot.
Flick also tweeted after the landing: "Seems my plane fell apart! Luckily we managed to land it."
Investigators collected some of the debris Monday and are also expected to take a close look at the plane itself.
"These types of failures are extremely rare," CBS News transportation analyst Mark Rosenker said. "They'll be tearing down those engines, part by part piece by piece to make sure they can understand exactly what happened."