Video: Plane Crashes Into Trailer

The pilot and another man, both in their late 50s or early 60s, suffered serious burns and were airlifted to Harborview Medical Center, said John Urquhart of the King County sheriff's office.

He said another man and woman in their 20s were also taken to Harborview. Their injuries were not believed to be serious, he said.

The conditions of the four were not known. Names and home towns were not released.

The Beechcraft plane, an A-36 Beech Bonanza, failed to gain altitude, crashed through a fence, hit a vehicle and caught on fire shortly after 6 p.m., said operations officer Cynthia Emery of the Federal Aviation Administration in Renton.

The FAA and the National Transportation Safety Board were investigating Sunday night.