At about 1050 eastern time, a Piper PA-28-181 was damaged while landing at Griffing-Sandusky Airport. The pilot and three passengers were seriously injured. The pilot said he was on approach to runway 27, a 3,559-foot runway, when he saw another airplane on a taxiway near the runway. He was not certain of the other airplanes intentions, so he decided to go around. The engine then began to lose power. He looked down and noticed that the mixture control was pulled back. He pushed the mixture in, but the airplane struck trees about a quarter mile beyond the departure end of the runway.