Small Plane Crashes on Atlanta Highway, Killing 4

A Piper PA-32 with four people on board crashed in Chamblee, Ga.

— -- Four people aboard a small plane were killed after the plane crashed on a busy stretch of an Atlanta highway Friday morning.

The plane crashed up against the median of the busy Interstate 285 and caught fire. Video taken by a passerby shows the tail of the plane engulfed and smoke billowing. Drivers slowly drive by the crash site, while others park along the side of the highway to look.

A man at the scene, Don McGee, described the crash as "like a bomb being dropped," WSB reported.

Gerald Smith told WSB he was driving a tractor trailer when he was almost hit by the plane.

"It was flying very low. It wasn't higher than the top of my truck," he said. "I guess it was just god telling me to slam on my brakes.. by the time I did hit the brakes, I heard an impact hit the front of my truck. "

Smith said, after he stopped the truck, "I looked back to my left ... and that plane was up against the wall burning."

The cause of the crash is unknown, said Eric Alleyne, an air safety investigator with the National Transportation Safety Board.

The investigation is ongoing, according to the NTSB, and will include looking at maintenance records and the pilot's experience.

The highway reopened in the late afternoon.

ABC News' Corinne Cathcart contributed to this report.