Sioux Falls, S.D. (KELO-AM) - The South Dakota Highway Patrol reports two motorcyclists were seriously injured in an accident Sunday evening on Interstate 90 near mile marker 394. The westbound lane of I90 was shut down as a helicopter landed to transport the driver of the motorcycle. Officials said a passenger on the motorcycle was also injured. The accident happened as a car was attempting to make an illegal U-turn. The driver of the car was cited for unlawful use of an interstate median and crossover. No other injuries were reported.