his sister, tammy miser, got a call with word that her brother was seriously injured. >> shawn and aof his coworkers were in the furnace room. and there was an explosion. and then there was a second more intense blast. >> what happened to him? >> he laid on the building floor, and the aluminum dust actually continued to burn through his flesh. >> and how severe were those burns? >> he had third- and fourth-degree burns between 92% to 100% of his body. >> the doctors said what to you? >> they told us that there wasn't any hope, that his internal organs were burned beyond repair. they wouldn't even bandage him. they just--they said that the only solution we had was to take him off of life support. >> shawn boone was 1 of 15 people killed in dust explosions that year. it was a turning point for carolyn merritt, who was then the head of the chemical safety board, the federal government's own experts who find the cause of the nation's worst industrial disasters. merritt ordered the most comprehensive investigation ever done on dust explosions. her conclusion: hundreds of industries create