The airplane was substantially damaged at about 1545 Eastern time during a forced landing after total loss of engine power. The commercial pilot sustained minor injuries and a passenger was not injured. Visual conditions prevailed. Shortly after takeoff, the pilot noted that the oil pressure gauge was below the green arc, and he elected to return. He then noted smoke in the cockpit, followed by a complete loss of engine power. The pilot performed a forced landing to a highway, about 1000 feet south-southeast of Runway 5. During the landing, the airplanes right wing struck a pole, and the lower forward portion of the fuselage sustained substantial damage. Initial examination revealed the crankshaft was seized. Oil streaks were observed on the underside of the engine cowling, and oil was present throughout the engine compartment. In addition, the oil filler cap was loose.