Abstract: At 11:30 a.m. on November 29, 2012, an employee and coworker were cleaning a vertical storage tank. The 6,000 gallon tank was 16 feet tall and previously contained methylene chloride and most recently dipropylene glycol methyl ether (DPM). The employee entered the tank with only a mask respirator, chemical goggles, gloves and coveralls similar to a Tyvek suit. The coworker remained at the top of the tank and the employee exited the tank, stating that the chemical order was too strong. The employee purchased some swimming goggles and re-entered the tank. The employee attempted to exit the tank and was about halfway up the ladder when he could not continue and let go of the ladder. Emergency Services found a few inches of a chemical at the bottom of the tank and measured only 12% oxygen in the tank during rescue operations. The employee was killed from injuries to their head and neck sustained in the fall from the ladder.