Storage of fertilizer grade ammonium nitrate (FGAN) is common worldwide. The material is stable when stored at ambient temperatures. However, ammonium nitrate is explosive when exposed to higher temperatures and/or a shock wave source. The presence of even 0.2% carbon adds to the blast potential. This paper summarizes the key finding of an ammonium nitrate explosion that occurred at a FGAN storage facility on 17 April 2013 in West, Texas, USA. 15 people were killed including12 emergency responders who were fighting a fire that occurred on the property before the explosion. Over 260 were injured. The key lessons learned are reviewed and recommendations are offered below. (C) 2017 Elsevier Ltd. All rights reserved.