Residents of San Francisco, California are advised to keep a map in their emergency kits. What kind of map? People who take the fire department training class (Neighborhood Emergency Response Team - NERT) learn to spot potable water hydrants, gas meters, soft story buildings, police call boxes and the chemical hazard warnings posted outside gas stations, car repair shops and construction sites. Until now, however, there are no maps with these features marked. This session will talk about the journey to creating these emergency maps with my local NERT using OpenStreetMap. It will include the best practices and lessons learned that can make this project useful for citizen mappers everywhere.