Abstract: On October 11, 2001, Employee #1 and a coworker were cleaning and closing in place two 20,000-gallon diesel tanks. The employees worked for Petrotech Southeast, Inc. (PSI), a professional environmental service company, which was contracted by Racetrac gas station. The closing of the tanks, in accordance with environmental regulations, required the cleaning and removal of diesel sludge contained in the tank. PSI established a confined space entry procedure to pressure wash the inside tank and had also contracted the services of Florida Waste Services to provide a vacuum truck and operator to transport and dispose the sludge and wash water from the tank. Employee #1 had been trained on confined space entry by Environmental Compliance Training Institute, Inc., in April, 2001 and his coworker was trained by STL Precision. The underground diesel tank, were the accident took place, was located in the south-east, back parking area of the Racetrac gas station. A metal manhole cover was covering a 34-inch opening leading to a 37-inch-deep sump area which led to the tank. Since the tank did not have an opening, Employee #1, with the assistance his coworker, made a round cut on the tank surface, large enough to enter the tank. According to the coworker, Employee #1 surveyed the working area the morning of the accident with the use of a Cannonball 2-inch monitoring device, and informed the coworker that it was safe to perform the cutting process with the use of electrical powered tools. The coworker indicated that Employee #1 requested some additional equipment needed to perform entry to the tank from their main office in Pampano Beach, FL. Since some of the equipment was missing on the morning of October 11, 2001, they postponed the entry and cleaning activity until the morning of October 12, 2001, and decided to conclude the workday by cutting the tank opening. After cutting most of the opening needed to perform entry the next day, Employee #1 and his coworker went to lunch and purchased some material at a local hardware store. Upon returning back at the site, the coworker suggested they return back the next morning to finish the cutting process, since only a small portion of the tank opening remained uncut. Employee #1, however, did not agree and without any tools, he stepped inside the 37-inch-deep opening and jumped twice on the piece of material that was being cut in the tank. On his second try, Employee #1 hit the material with such a force that the material broke loose. Employee #1 was not able to balance himself and fell 13 feet into the tank. The coworker indicated that Employee #1 was able to stand up inside the tank but was quickly overcome by the gases and lack of oxygen inside the tank. The coworker, equipped with a 3M half face mask with dual OV cartridges and an electrical extension cord tied around his waist, attempted to rescue Employee #1. Not being able to do so, the coworker was pulled out of the tank. On his way out, the coworker lost consciousness due to the atmosphere condition inside the tank and was treated immediately on-site by emergency personnel. A Lakeland Fire Department Rescue Team member confirmed that Employee #1 had no vital signs while in the tank. Employee #1 was killed by asphyxia due to aspiration of oil products.