Suppose you were designing a database to store accidents, and you had the need to categorize them, are the categories below sufficient? By accident here I mean non-intentional occurrences which lead to undesirable consequences... 1. Vehicle Accidents involving vehicles with at least 4 wheels 2. Cycles (is there a better name for this?) Vehicles with three wheels and less 3. Buildings 4. Infrastructure, e.g. bridges collapsing etc 5. Marine How do you differentiate someone drowning from a boat sinking? 6. Aircraft 7. Ordinance? Old military appliances that tend to explode? 8. Domestic Accidents which happen at home. But if a fire takes place at home, and a fire takes place at a factory, are these two different categories or should they be the same, or both? 9. Industrial