1. Division of Emergency Medicine, Children’s National Hospital, 111 Michigan Ave NW, Washington, DC 20010, USA
2. Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, 2300 I Street NW, Washington, DC 20037, USA
3. The National Center for Fatality Review & Prevention, 2395 Jolly Road Suite 120, Okemos, MI 48864, USA
4. Department of Pediatrics, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD 21201, USA