On September 21, 2015, at 12:03 p.m., an employee of Bonefish Grill in Centreville, Virginia, called the Fairfax County 911 Center to report a gasoline odor. The Fairfax County Fire and Rescue Department (FCFRD) immediately dispatched units to the restaurant in the Centre Ridge Marketplace shopping center. After arriving at the scene, firefighters confirmed everyone had left the restaurant; they established an incident command center, and they began the investigation. They did not detect the presence of flammable vapor inside Bonefish Grill and ruled out a natural gas leak; however, they noted a gasoline odor coming from the storm drains at the shopping center. Firefighters detected the presence of flammable vapor in most of the storm drains behind Bonefish Grill and Chipotle. Flammable vapor in some storm drains in front of Bonefish Grill was as high as 100 percent of the lower explosive limit (LEL); however, no liquid was visible in the storm drains.