One person was killed after a motorcycle crash in Twin Falls Saturday night. It happened just before 9:30 p.m. on 3300 East road.   23 year old Brandon Gratriex of Susanville, Ca, and his passenger, 20 year old Kesia Lewis of  Twin Falls, were riding a 2006 Kawasaki Motorcycle southbound on 3300 East.  Gratriex failed to negotiate a curve.  The vehicle went off the roadway, through a wooden fence and into a field. Both Gratriex and Lewis were thrown from the motorcycle. Gratriex was pronounced dead at the scene.  Lewis was initially taken by ground ambulance to St. Luke's Magic Valley Medical Center in Twin Falls and subsequently taken by air ambulance to St. Alphonsus Regional Medical Center in Boise.   Neither of them were wearing helmets and it is believed that speed was a factor in this crash.