Toronto police have launched a public mischief investigation after a car was suspended from a bridge that spans one of the city’s busiest arteries early Wednesday, spooking morning commuters and confusing emergency responders.

A blue sedan was spotted swaying back-and-forth from a rope underneath the Millwood Overpass Bridge, south of Don Mills Road. The Honda Civic vehicle’s interior appeared to be burned out and its windows missing.

Video from the CTV Toronto helicopter showed the vehicle slowly spinning in the wind, supported by two of the bridge’s beams.

As emergency crews worked to bring the car to the ground, onlookers were seen snapping pictures of the unusual sight.

“I've never ever seen anything like that before,” one cyclist told CTV New’s Peter Akman. “I've driven these trails for years and years and never seen anything like this. This is hilarious."

Police initially chalked it up to a movie shoot, but later said no such filming was authorized.

“At this time, it is believed this incident was intended as a prank,” Const. Caroline de Kloet said in a release Wednesday afternoon. “This incident resulted in the use of significant resources that were not available to attend to genuine emergency calls for service.”

City of Toronto spokesperson Wynna Brown also confirmed that the city did not issue a permit in relation to the stunt.

Police said the right southbound lane of the Don Valley Parkway was blocked at Millwood Road. The vehicle was suspended about 200 metres away from the busy parkway.

"There’s a walkway, there’s a bicycle path that runs immediately underneath where the car was hanging, so the danger was very high,” said Sgt. Glenn Russell with the Toronto Police Service.

Firefighters safely dropped the vehicle to the ground shortly before 10 a.m.

Speaking to reporters at an unrelated event, Mayor John Tory said he has no plausible explanation for the car’s presence beneath the bridge.

“When I was shown the pictures I was just shaking my head in disbelief that it could have happened,” he said. “If it’s a prank, then obviously the law should apply to people who are doing things like that.”

The prank theory is not unfounded. In 2008, CTV Vancouver reported that University of British Columbia engineering students were believed to be responsible for suspending a Volkswagen Beetle under the Lions Gate Bridge.

Students at both the University of Toronto and Ryerson University have denied any involvement.

Anyone with information is asked to contact police at 416-808-5500, Crime Stoppers anonymously at 416-222-TIPS (8477), online at www.222tips.com, or text TOR and your message to CRIMES (274637).

With a report from CTV News’ Peter Akman and with files from CTV Toronto and CP24