2000 Subaru Forester Steering problems

Steering locked up twice while driving, both times shortly after making sharp right turn out of home driveway. The first time, the driver was unable to turn the steering wheel at all after making the hard right turn out of the driveway. Then the steering returned to normal after wiggling the steering wheel. The second time, the driver made a hard right turn out of the driveway and then straightened out and proceed about twenty yards to an intersection at which point the driver was unable to turn the steering wheel for a right turn while driving at approximately 10 mph. The steering wheel simply would not turn. Then after several seconds the steering returned to normal. *Nm