A small airplane crashed Tuesday while trying to take off at a Lebanon County airport, injuring four people. The crash occurred about 5:30 p.m. at Deck Airport in Jackson Township southwest of Myerstown, just across the Berks County line. State police were on hand securing the scene, but troopers said they couldn't comment on what happened. The Federal Aviation Administration will be handling the investigation, troopers said, with officials expected to arrive Wednesday morning. Troopers did confirm that four males - the pilot and three passengers - were injured in the crash and all were taken by ambulance to Penn State Milton S. Hershey Medical Center. While they couldn't provide the identities of the pilot or passengers, troopers said the passengers consisted of a man and his two adult sons. The group was headed to southwest Illinois. Gary Deck Sr., who helps manage the airport owned by his father, Clyde E. Deck, witnessed the crash. Deck said he spoke with the group just before they took off, warning the pilot about low visibility caused by a thick fog in the area. As the plane, which he described as a Beechcraft Bonanza, began to lift off, Deck realized there was a problem. He said the aircraft wasn't lifting off like it should be, hanging only about 200 feet off the ground, before it veered sharply to the left. "I thought, 'He's at the point of no return here and he's not high enough,' " Deck said. "I said, 'I have a gut feeling the guy isn't going to make it.' " Just past the end of the runway it sounded like the plane's engine stalled, Deck said. The craft came crashing down onto its belly, bouncing and skidding across a muddy field to the south of the airport. Deck jumped into his pickup truck and raced to the scene. When he arrived, one of the passengers was lying unconscious in the grass and another was unconscious in the back seat, Deck said. The pilot was conscious, but seemed dazed, and the other passenger was lying on one of the plane's wings calling for help, Deck said. Deck said there was no fire and no smell of leaking fuel. He called 9-1-1, leaving another witness at the scene as he went to wait by the road and help guide emergency responders across the dark field to the crash site. Deck said the passengers had arrived Wednesday on business and were heading home to Illinois. They had a scheduled stop in West Virginia, he added. Troopers said all four men were conscious when they left for the hospital. Information on their conditions could not be immediately obtained.