Three persons were injured in a truck accident at 7:20 this morning about 3 miles south of Mt. Vernon on Route 37. One of the two trucks, ap parently traveling with a cardi nal, overturned in front of the Bakerville Baptist church. The driver, William Jamer son, 43, Essex, Ill., was pin ned under his trailer- truck for a short time, according to a police report. His wife, Maxine Jamerson, 48, was a passenger in the truck. Both were taken to Good Sa maritan Hospital According to a hospital spokesman, their in juries appeared to be minor. The driver of the second truck, Roy Pennington, 24, Che banese, Ill., was also taken to Good Samaritan with apparent ly minor injuries. State police had no informa tion on the cause of the acci dent. A witness at the scene of the accident reported that the side of the truck that did not overturn was badly dented.