Abstract: Employee #1, a warehouse operator, dropped his safety glasses into the compartment of a railroad tank car that was being filled with aerosol. The aerosol was blown through a line by low pressure nitrogen gas. After Employee #1 notified coworkers and his supervisor, the material flow was turned off but not the gas. Wearing a gas mask, Employee #1 entered the railcar through a manhole. He was overcome and fell to the bottom of the tank. Employee #2, his supervisor, entered the railcar in a rescue attempt but was also overcome. Two other employees wearing gas masks attempted an unsuccessful rescue. Coworkers who donned SCBA removed the two bodies. Neither Employee #1 nor Employee #2 could be revived. Two hours later the tank air was tested and found to be at 14 percent oxygen.