Firefighter Ophery H. Gibson, Jr was guiding in a helicopter to land at the Naval Ordinance Lab. He ignited a "smoke bomb" in a bucket to determine wind direction for the incoming aircraft. When it didn't produce smoke, Firefighter Gibson went to check on it. As he stood over the bucket the "smoke bomb" exploded, went through his chest, and killed him. Upon investigation, it was discovered that the "smoke bomb" was actually a phosphorus grenade.