ATLANTA -- Seconds before slamming into a metro Atlanta freeway, a pilot radioed air traffic controllers to say he was struggling to gain altitude, authorities said.
The pilot's last radio transmissions before the fiery crash that killed all four people aboard came about two minutes after departure from DeKalb Peachtree Airport shortly after 10 a.m. on May 8, according to a preliminary report released Tuesday by the National Transportation Safety Board.
"Zero-two-victor, I'm having some problem climbing here," the report quotes the pilot as saying. "Zero-two-victor; we're going down here at the intersection."
Scars across the pavement of four lanes of busy Interstate 285 were found by investigators. They ended at a concrete highway divider, where the wreckage of the Piper PA-32 was found. The plane had stopped at the airport just north of Atlanta and was heading to Oxford, Mississippi, when it crashed, authorities have said.
Shortly after takeoff, a witness who was about 2,300 feet from the departure end of the runway said the airplane was moving "extremely slow" as it flew about 75 to 100 feet over his head, the report states.
"He went on to say that the engine sounded normal and despite the slow speed the airplane was not 'wobbling' left to right," the report states. "He continued to watch the airplane as it flew out of his view."
The plane grazed the hood of a semitrailer on the freeway - one of Georgia's busiest stretches of highway - but no one on the ground was seriously hurt.
The driver of the semitrailer, Gerald Smith, saw the plane head right for him.
"It's like it was coming directly in my windshield," Smith told CBS News. "So I hit the brakes and by that time the plane came directly across my hood."
It grazed Smith's truck moments before crashing.
"Made my way out the truck to see if I could help," Smith said. "By the time I got over there it was blazed up so bad, there wasn't nothing anybody could do."
The report released Tuesday is preliminary in nature and does not conclude what caused the plane to crash. A final report is not expected for several months.
Officials have been working to positively identify the remains of those killed in a process that has taken several days, DeKalb County Medical Examiner Patrick Bailey has said.
Greg Byrd, his sons, Phillip and Christopher, and Jackie Kulzer, Christopher's fiancée, were heading to Ole Miss to see another of Greg's sons, Robert, graduate when the plane crashed.