A study called "Safety in Numbers: Are Major Cities the Safest Places in the United States?" was published this week by the American College of Emergency Physicians. The researchers, led by Sage R. Myers of the Children's Hospital of Philadelphia, noted that until their work, the overall injury risk in urban areas versus suburban and rural areas had not been fully described.

So Myers's team attempted to classify deaths from injuries "across the rural-urban continuum." They looked at data on 1,295,919 deaths from injuries in 3,141 U.S. counties from 1999 to 2006. These deaths were caused by car accidents, shootings, falls, drowning, suffocation, and more.

"Injury mortality increased with increasing rurality," the scientists wrote. "Urban counties demonstrated the lowest death rates,