(Drewsey, OR) -- Officials say 30 swans, geese and other waterfowl were killed in a mass casualty event east of Burns in Eastern Oregon last week. Think Wild, a bird rescue group in Bend, was asked to care for one Tundra Swan that survived. Biologists think a combination of a lunar eclipse and a snow storm caused the birds to become disoriented and fly into power lines, light poles, and the ground. The birds were either killed or too severely injured to heal. The bird that survived is being cared for until it can recover.