"The Shag Harbour UFO Incident was the documented impact of an unknown large object into Shag Harbour, Nova Scotia, in October 1967. The impact was investigated by various Canadian government agencies, and at least one underwater search was launched to locate the remains of any associated objects. The Canadian government declared that no known aircraft was involved and the source of the impact remains unknown to this day. It is one of very few cases where governmental agency documents have formally declared an unidentified flying object was involved. Several interviewed military witnesses, including a diver involved in an attempted recovery, have claimed an alien spacecraft was responsible."