A detailed case history of the events surrounding an exceptionally catastrophic midair collision of two cropduster planes involved in the nighttime spraying of pesticides is reported. Killed in the accident were both pilots, as well as a woman occupying a farm home which was struck by one of the planes and subsequently destroyed by fire. The accident also precipitated two heart attacks, one of them fatal, among those witnessing the accident. A herd of dairy cattle was also contaminated by cargo spillage and debris from the crash, resulting in the death of two cows and necessitating that milk from the herd be quarantined. Some of the various problems confronting aerial applicators are also presented and discussed, as is the need for greater medical supervision of agricultural pesticide dispersal.