Three Fort Worth residents were killed Saturday afternoon when their plane crashed within a minute of taking off from a private Kaufman County airstrip, witnesses said.

Shelley Bradley said she was standing near the grassy airstrip in the 18000 block of County Road 4072, about 10 miles west of the town of Kemp, when she noticed that the plane appeared to be in trouble as it lost airspeed.

"He took off and the wind changed," Ms. Bradley said. "He should have banked to the right, but he banked to the left."

The pilot tried to correct the direction of the plane as it plummeted toward the open field.

"He was flapping his wings as if he was saying goodbye, but then we realized he was in trouble," Ms. Bradley said.

The plane burst into flames when it crashed, and black smoke quickly rose from the accident scene. The crash ignited a brush fire covering about two acres, authorities said.

Authorities were trying to determine the cause of the crash.

Kaufman County Sheriff's spokesman Sgt. Bryan Francis said his agency was notified of the crash at 3:40 p.m. Authorities then discovered that the three people died at the crash site, which is in southwestern Kaufman County.

Four local fire departments, the Texas Department of Public Safety and the Federal Aviation Administration were notified, Sgt. Francis said.

Kemp resident Ray Andrews was at the Indian Oaks Golf Course a few miles from the crash when golfers told him that they heard a loud explosion and saw smoke. Mr. Andrews got into a golf cart and went near the scene.

"There was still fire," Mr. Andrews said Saturday evening. "It doesn't even resemble a plane."

The plane's debris scattered at least 20 feet, and the wings and cockpit were charred, he said.

The pilot, his wife and their son, all of Fort Worth, had just left a monthly aviation meeting with friends. They planned to fly back to Fort Worth. Their names were being withheld until relatives could be notified.

The pilot "said bye and we'll see you next month at our meeting" before he jumped into the plane, Ms. Bradley said. "Five minutes before, I was talking to him and telling him that he had big feet."

Arthur Akridge, who lives along CR 4072, said he knew the pilot 10 years and considered him one of his best friends.

"It's just awful," Mr. Akridge said.

Staff writer Tiara M. Ellis contributed to this report.