The pilot radioed air traffic controllers at around 7:40 p.m. local time Monday reporting that his engine had shut down.
Metro Nashville Police said the control tower granted approval for an emergency landing at the John C. Tune Airport, just west of downtown Nashville, but the pilot said the aircraft wouldn't make it to runway.
The plane crashed along a stretch of Interstate 40, behind a Costco store, and burst into flames.
Aaron McCarter, a National Transportation Safety Board (NTSB) aircraft accident investigator, told reporters Tuesday the agency is working with the Canadian embassy to identify the victims.
It would be up to local authorities in Nashville to release any names, an NTSB spokesperson said in an email to CBC News on Tuesday night.
He said the flight took off from Ontario, but did not have the specific location, and that all indications suggest the aircraft was bound for John C. Tune.
According to FlightAware, a website that tracks flight activity, it took off from the area Milton, 55 kilometres west of Toronto.
Global Affairs Canada said consular officials are are in contact with authorities in Tennessee and will provide consular assistance to the victims' families, but would not provide further information, citing privacy considerations.
The pilot of the plane told air traffic controllers he could see the runway they were clearing for an emergency landing, according to a recording of the radio transmissions. But he said he couldn't reach it.
"I'm going to be landing — I don't know where!" the pilot said before the plane crashed.
He said he had overflown the airport about 762 metres and had circled around in an attempt to land, according to a recording of their radio transmissions.
They cleared runway two at the airport, and urged him to glide the plane down. But the plane had already descended to 488 metres by then, he said."I'm too far away. I'm not going to make it," he said.
That was the last they heard from the plane, which dropped off radar as it lost altitude.
The plane crashed as Matthew Wiser was driving on the interstate, and he posted a photo of the fiery wreckage on social media.
"I saw an airplane essentially crash out of the sky, fall out of the sky, and hit the ground at around a 45-degree angle," Wiser said in a phone interview with The Associated Press.
"When it hit the ground, there was a 30- to 40-foot [nine- to 12-metre] explosion of fire. And all of the traffic on the interstate stopped and kind of processed what they saw."
Air traffic controllers then directed a local helicopter crew to survey the approach to the airport in search of the plane, while keeping other aircraft out of the emergency area.
Within minutes, a flood of emergency vehicles was speeding to the scene, Wiser said.
A night view of the wreck of a small plane that crashed on a grassy area, with yellow police tape stretch across the site.
They discovered that the plane burst into flames in the grass, just off the highway and behind a Costco on the city's west side, nearly five kilometres south of the general aviation airport.
There were no injuries to drivers on the interstate, Nashville Fire Department spokesperson Kendra Loney said Monday night. Authorities said no vehicles or buildings on the ground were damaged.
The plane referred to in the air traffic control radio recordings was a Piper PA-32R, made in 1978 and based in Ontario, according to Canada's civil aircraft registry.
"We don't know if the aircraft had any history of problems," NTSB's McCarter said. "That's something that's got to be looked at later on."
He said the plane made several stops — including one in Erie, Penn., and another in Mount Sterling, Ky. — prior to the pilot radioing air traffic controllers at the airport. He said the stops were likely to refuel.
McCarter said he was in possession of the plane's maintenance records, but he did not have details of the pilot's flight history.
It's also not yet clear if there were any miscommunications between the pilot and air traffic controllers, he added.
"We are in the infancy of this investigation," McCarter told media, saying a factual report would be put together in the next nine to 12 months to determine the probable cause of the crash.
