The pilot of the single-engine plane that crashed near downtown Nashville told air traffic controllers that he could see the runway they were clearing for the emergency landing. But he said he couldn't reach it.

The pilot said before the plane crashed beside Highway 40, killing all five people on board, "I'll land - I don't know where!"

Aaron McCarter, an investigator with the National Transportation Safety Board, said at a press conference on Tuesday that the plane was carrying another adult and three children, adding that the five were Canadian citizens and that the agency is working with the Canadian government to identify them.

He confirmed it is too early to know the cause of the accident. Investigators still do not know the pilot's qualifications or the number of flight hours he had, but his experience is one of the things they will investigate.

Global Affairs Canada said in a statement that it is aware of reports of the deaths of five Canadians in Tennessee but no details will be released due to privacy considerations.

Liam Macdonald, a board spokesperson, said in an email that the Canadian Transportation Safety Board has appointed a representative to the investigation led by U.S. authorities.

The pilot contacted air traffic controllers around 7:40 p.m. Monday and reported that his engine had stopped working, and that he was flying over John C. Tune Airport, west of downtown, at 2,500 feet, circling it in an attempt to land, according to his radio broadcast recording.

They cleared the second runway at the airport and urged him to bring the plane down. But he said the plane had already descended to 1,600 feet (488 meters) by that time.

He said, "I'm too far, I won't be able to make it."

That was the last they heard from the plane, which disappeared from radar after losing altitude.

The plane crashed while Matthew Weiser was driving on the highway, and he posted a photo of the burning wreckage on social media.

Weiser said in a phone interview: "I saw a plane crash and fall from the sky, hitting the ground at about a 45-degree angle." "When it hit the ground, there was an explosion about 30 to 40 feet. All the traffic on the highway stopped and processed what they saw somewhat.

Then air traffic controllers directed the helicopter crew to scan the airport approach area for the plane, keeping other aircraft out of the emergency zone. Weiser said that within minutes, a flood of emergency vehicles rushed to the scene.

They found that the plane had caught fire among the grass, off the highway and behind Costco on the west side of the city, about 3 miles (4.8 kilometers) south of the general aviation airport.

Kendra Loney, a spokesperson for the Nashville Fire Department, said there were no injuries among the drivers on the highway. Authorities said no vehicles or buildings on the ground were damaged.

The plane referred to in the radio recordings is a Piper PA-32R model, manufactured in 1978 and based in Ontario, according to the Canadian civil aircraft registry.

McCarter said the flight originated in Ontario and stopped along the way, likely to refuel, including in Erie, Pennsylvania, and Mount Sterling, Kentucky. McCarter added that before the pilot declared an emergency over the radio, the plane was on a normal flight path and no mechanical issues were reported during its arrival from the Kentucky airport.

The Federal Aviation Administration and the National Transportation Safety Board are investigating. McCarter said they have packaged the wreckage to transport it to a facility in Springfield, Tennessee, where the plane will be reassembled.

He added that investigators do not know why the pilot decided to circle the airport before the accident. He noted that the plane's approach was perpendicular to the highway when it hit the ground.

The NTSB will have a preliminary report in about 10 days. The full report will take about nine months.