A small plane crashed and flipped upside down in the front yard of a house near Covington Saturday. The pilot, the lone occupant, was airlifted to Harborview Medical Center, where he was upgraded from critical to serious condition Monday, officials said.

Although the Cessna 150 crashed into a residential area near Crest Airpark, no one was injured on the ground. One eye witness reported that he saw the plane sideways in the air, and that it banked hard behind some trees and hoems before he lost sight of it, said Mountain View Fire & rescue.

Neighbor Robby Thompson said, “I just heard a loud, loud crash. It sounded like someone was driving really fast and hit a car.”

He said he looked out his bedroom window and saw the mangled wreck of an aircraft and neighbors scrambling to help the injured pilot.

“They were climbing over the wing, and they were making sure he was OK. They were telling him not to move because, I guess, he had a lot of head trauma.”

Tim Perciful of King County Fire District 44 said, “It’s amazing – the people that came and helped … helped us tremendously. It sounds like they actually turned off the fuel line and the mast switch. On top of that, they also helped stabilize him.”

Witnesses said the pilot was going in and out of consciousness.

Robert Regan was in his garage when he heard the loud crash and ran outside to find the plane in his front yard. “The engine was still running when it hit the ground,” he said. “It was a big thud.”

Investigators said the plane originated out of Crest Airpark, only a couple of hundred yards away from the crash site.

“The eyewitness I spoke to said he heard a noise, and he saw the plane knife-edge to the ground,” Perciful said.

Regan said of the plane wreckage in the front yard: “The trees actually protect us here. Obviously he clipped the trees – that stopped the airplane from coming any further to the house.”

Federal Aviation Administration spokesman Allen Kenitzer said the plane was a Cessna 150 and that the cause of the crash was unknown.

FAA employees have moved the plane into a hangar and begun an investigation on what caused the crash.