Abstract: On February 8, 2005, Employee #1 drove a vacuum truck to a remote oil & gas tank battery to pump oil from a gun barrel tank to storage tank. Brine water was then vacuumed from the gun barrel tank and transported to a drilling mud circulating tank at another location. Several trips were made. The day was cold, foggy and cloudy with a light rain falling and very little wind. This tank battery was located in a low area. The vacuum truck had not been grounded, nor was there a bonding cable from the truck to the gun barrel tank. The four inch vacuum hose from the truck ran up a stairway and along the length of an elevated walkway, entered the gun barrel tank through an open manway, and extended down into the brine water. Employee #1 was on the walkway at the open manway when an explosion blew the bottom from the tank, and threw him against the side of the storage tank, killing him.