Abstract: At 2:00 p.m. on May 11, 1990, Employee #1 and a coworker were on top of the #2 silo, trying to free the rotary valve paddles, which were stuck with calcium chloride. They put down the handle of the nearby electrical cabinet to deenergize the valve and removed the valve inspection plate to gain access to the paddles. When they were unable to move the valve with a pipe wrench, the coworker went to the ground, 60 ft below, to send up a hammer by rope. Employee #1 then used the hammer on the paddles. Employee #1 and the coworker had forgotten two-way radios, so Employee #1 called down to the coworker for pliers and then asked him to run the valve briefly. The coworker walked about 100 ft out of signal and hearing range into the building to briefly operate the valve at ground level. At this point, Employee #1 did not remember clearly. He apparently reenergized the valve and forgot to deenergize it again. When he put his right hand in to move the calcium chloride, the system was reenergized, and the paddle cut off the ends of three fingers and his thumb.