BURLINGTON - Two investigators with the National Transportation Safety Board spent Monday combing through the debris of a crashed airplane, looking for clues that will point to the cause of the crash that occurred Sunday.

At the same time, two other NTSB officials spoke with witnesses at the Lawrence County Airpark, gathering additional information.

The plane, carrying South Point area physician Michael Young, his daughter Ginny Young and a friend, Charles Lampe, of Lexington, Ky., crashed in a field two-tenths of a mile from the airpark Sunday afternoon. All three people on board were killed.

Small engine aircraft do not have the black box that is the focus of investigations in crashes involving larger airplanes. But Ohio State Highway Patrol Trooper Michael Gore said other air plane features will be useful in determining what happened.

"They will pay attention to the engine and the gauges, to get any information they can about what the cause of the crash was," Gore said. "They have a dash-mounted device kind of like a GPS and it will have information, if it isn't damaged. They can determine wind speed and other factors from that."

The plane's engine was loaded on a backhoe and taken to a hangar at the airpark, where investigators will examine it. Gore said other parts of the wreckage may yield vital information as well.

As investigators and state troopers made their way across the wreck site, Burlington resident Danny Snyder watched quietly from the edge of County Road 1.

"Dr. Young was my doctor," he said. "I just saw him Thursday. I talked to him just last week. I was in to see a surgeon and he was there at the office and we talked. He just got back from Iraq," Snyder said.

Young was a flight surgeon with the West Virginia National Guard 772nd Aviation Battalion. He had recently returned from a 90-day tour of duty in Iraq, according to Major Mike Cadle, spokesman for the West Virginia National Guard.

Snyder, who lives near the area where the plane crashed, said he heard the sirens Sunday afternoon and assumed there had either been a roadway accident or a plane crash. He said he was shocked and saddened when he learned who the victims were.

"I really liked him. My mom thought the world of him," Snyder said of Dr. Young. "It's going to be hard to replace him."