Twenty-five minutes after midnight on Friday October 20, 1944, an American courier plane of type Consolidated C 87 Liberator crashed near Lake Anten, around 11 km NW of Alingsås. The whole crew died.
The plane was one of a group of five that lifted from England heading towards Bromma in Stockholm. However, bad weather forced them to land at Torslanda in Göteborg. Four succeeded, but plane NC-18618 never arrived. The cause has never been established, but stubborn rumours tell of bullet holes in the plane. If these were new or from another flight is not known.
The plane carried a load of 110 drums of oil and was a part of a secret war operation named Project Sonnie. The operation was so sensitive that after the accident it was claimed in the USA that the plane crashed during a mission in the far east.
A memorial was raised at the crash site a year after the accident. The inauguration took place on Sunday, 27 May 1945 and was attended by more than a thousand persons. In addition to representatives of the Swedish military, police and firemen, there were some guests from the USA Air Force.