The Bombardier Challenger 600 series jet has crashed on the I-75 highway in US state of Florida.

A private passenger jet crash-landed on a busy highway in Florida in the United States and collided with two vehicles on the ground in a fiery accident that killed two people, authorities and witnesses said.

Moments before the jet with five people on board slammed into the highway on Friday, the pilot calmly told an airport controller that the aircraft “was not going to make the runway” since it had lost both engines.

The jet was bound for the airport in Naples when it tried to make an emergency landing on Interstate 75. But witnesses say it collided with a vehicle – the wing of the plane dragging a car before slamming into a wall. An explosion followed, with flames and black smoke rising from the scene.

Two people were killed, according to the Collier County Sheriff’s Office, but it was not immediately known whether the victims had been passengers on the plane or were on the ground.

Federal authorities have launched an investigation into the crash near Naples, just north of where the interstate heads east towards Fort Lauderdale along what is known as Alligator Alley.

The plane had taken off from an airport at The Ohio State University in Columbus, Ohio, at about 1pm. It was scheduled to land in Naples around the time of the crash, Naples Airport Authority spokesperson Robin King said, when pilot contacted the tower requesting an emergency landing.

“Got that. Emergency. Clear to land. Runway. Two. Three,” the air traffic controller responded to the pilot, in audio obtained by The Associated Press.

“We’re clear to land, but we’re not gonna make the runway. We’ve lost both engines,” the pilot calmly replied.

‘The wing pulverised a car’

The tower lost contact, and then airport workers saw the smoke from the interstate just a few miles away, King said.

King said they sent fire trucks with special foam to the scene, and three of the five people on board were taken from the wreckage alive.

Brianna Walker saw the wing of the plane drag the car in front of hers and slam into the wall.

“It’s seconds that separated us from the car in front of us,” she said. “The wing pulverised this one car.”

Walker and her friend spotted the plane moments before it hit the highway, allowing her friend to pull over before the crash.

“The plane was over our heads by inches,” she said. “It took a hard right and skid across the highway.”

According to the FlightAware aircraft tracker, the plane was operated by Hop-a-Jet Worldwide Charter based in Fort Lauderdale, Florida. The aircraft had been scheduled to fly back to Fort Lauderdale on Friday afternoon.

Federal authorities said a preliminary report about the cause of the crash can be expected in 30 days.