In 13 years of police work, Sgt. Gwen White-Erickson has seen plenty of rubble. But the Michigan state police fire investigator wasn't ready for what greeted her when she pulled up to TRW's plant in Romeo, Mich., last Dec. 17.
An hour and a half earlier, an explosion of automobile air bag propellant had leveled a concrete block building that was about 40 feet long and wide.
"The walls sort of blew out; the roof just sort of collapsed in," she recalled. "It was just a bunch of rubble. . . . I've never seen concrete blocks laid out that way."
It was an awesome display of the power of the chemicals used to inflate air bags _ and an unpleasant side of the air bag success story.
Anyone who watches TV has seen videotape of air bags inflating in slow motion just in time to cushion a test dummy before it slams into a steering column. By all accounts, the widespread installation of air bags in cars is saving lives and preventing injuries, and the devices themselves have been remarkably reliable.
Federal safety regulators forecast that 2,400 lives will have been saved in the five years ending in 1995 and 29,000 serious injuries avoided, thanks to air bags _ nylon sacks that inflate with nitrogen gas in a fraction of a second to cushion passengers in a crash.
But manufacturing those systems has proved on occasion to be a risky business, one that involves working with highly unstable and explosive chemicals.
Since 1988, there have been at least 18 explosions or fires in factories that make air bag components, mix the propellant that inflates air bags or handle waste products from either. No one has been killed, but 23 workers have been injured, four seriously. Eleven workers at the Romeo plant, about 30 miles north of Detroit, were slightly injured and were treated for smoke inhalation and trauma.
But the accidents not only have affected workers; they are one reason why car makers have been unable to install air bags in more models more quickly.
In one instance, a factory was shut down for almost a year, and it created shortages of air bag propellant that forced Ford Motor Co. to build 75,000 1991 Lincolns without passenger-side air bags. They were later retrofitted.
Still, there is no statistical evidence that the air bag industry's safety record is any worse than any other handling highly explosive substances _ or any other industry, period.