FESTUS, Mo. (AP) — A father and son are hospitalized after their small plane crashed south of St. Louis.

The crash happened Monday night after takeoff from the Festus Airport in Jefferson County. Authorities say the plane went down in a farm field.

The 60-year-old father and his son, in his 40s, were both conscious and talking to authorities, describing a malfunction with the plane.

Their injuries are not believed to be life-threatening. Their names were not released.

Federal investigators were looking into the cause of the accident.