No one needs to tell Steven Stallbaumer about the dangers of working in grain elevators.

He was unloading fertilizer outside a Kansas elevator in 1998 when it exploded, killing seven workers. The blast knocked Stallbaumer underneath a railroad car, and he figures that saved his life. A big motor fell from the top of the elevator and landed beside the dump truck where he had been working.

"All I heard is a boom, boom," Stallbaumer said.

A similar blast killed six people last weekend at the Bartlett Grain Co. elevator in Atchison, about 50 miles northwest of Kansas City. Experts say such deadly accidents have become less frequent and grain elevators are safer than they've ever been thanks to rules and procedures established after a rash of explosions killed 50 people in four states in six days in the late 1970s. But they also agree only so much can be done to prevent explosions.

"We do work in a very dangerous environment, and unfortunately there have been accidents," said Darwin Franzen, the general manager at Farmer's Cooperative Co. in Hinton, Iowa. "You try as hard as you can, but sometimes there is something that causes these terrible accidents to occur."

Farmers take corn and other grain to elevators to be stored and sometimes processed before it's marketed and sold. There are more than 10,000 commercial grain-handling operations nationwide, with large numbers in Illinois, Iowa, Kansas, Minnesota, Nebraska and Texas. Fine, highly combustible dust particles flow through the buildings as the grain is moved. A spark from equipment or an overheated bearing on a conveyor can ignite the dust, sending a pressure wave that detonates the rest of the dust floating in the facility.

Stallbaumer, now 50, had worked at the DeBruce Grain Co. elevator in Haysville, southwest of Wichita, for 13 years before it exploded. He'd been in the industry since he was 18 or 19, working first as a grain inspector and later at several elevators in the area. He said he'd always been worried about an explosion.

"If the place ain't clean, that is going to blow up," he said. "It just takes a matter of time. There has to be a certain element — the dust, then there has to be a spark and she will go off like a time bomb."

The explosion at the Bartlett elevator happened while workers were loading a train with corn. Figuring out what sparked it could take up to six months, said Scott Allen, spokesman for the Occupational Safety and Health Administration. The elevator had not been inspected since Bartlett purchased it about five years ago, although OSHA has stepped up inspections in Kansas since the DeBruce explosion. Bartlett officials declined to answer questions about their safety procedures or facilities.

OSHA has several inspectors at the Bartlett elevator and will be interviewing employees and company officials. But, investigators can't always determine what happened because the blast can destroy evidence.

"It's kind of like going into a building that's burned and trying to determine what happened," Allen said.

The agency blamed the 1998 blast at the DeBruce elevator on corporate decisions to allow grain dust to accumulate, skip repairs and abandon preventive maintenance of equipment. Investigators found the most probable ignition source was a conveyor belt roller bearing that had seized up from lack of lubrication and become hot enough to ignite dust in the area.

Federal regulations have become tougher since the late 1970s, when the nation saw an average of 25 grain elevator explosions each year. During six days in December 1977, grain elevators exploded in Louisiana, Texas, Illinois and Mississippi, killing 50 people and injuring another 50.

The government's top grain inspector threatened to close down all U.S. export grain elevators until safety could be assured. The industry responded by doing research on grain dust explosions, modifying equipment and building safer facilities. For example, many companies now move grain from the bottom to the top of storage facilities with outdoor "bucket elevators." That way, if a part should overheat or create a spark, it won't come in contact with dust inside the building.

"When you look at the history of dust explosions, those (interior) elevators have been a primary source where explosions have most often occurred," said Dirk Maier, head of the Department of Grain Science and Industry at Kansas State University.

OSHA revamped its regulations in 1987. Experts say a key to reducing explosions has been simple rules, such as banning welding when grain is being moved and dust is kicked up. Many explosions also were caused by sparks from malfunctioning machines, which are now watched more closely to ensure they're well-oiled and don't overheat. Other improvements have included stricter codes for electrical systems and valves that relieve pressure if an explosion occurs.

In Kansas, some elevators now use magnets to pull out bits of metal that can mix with grain when it's harvested or transported, reducing the risk of a possible spark.

The result has been fewer than nine explosions per year between 2001 and 2005, the latest period for which OSHA has data available. Explosions also have become less deadly as automation has reduced the number of workers in many facilities. The number of fatalities dropped from an average of 21 in the late 1970s to about one a year between 2001 and 2005.

Maier said the grain industry has been "very proactive" in making changes to improve safety.

"None of us want to see any of our employees injured," Franzen said. His company, which has elevators in four Iowa communities, has mandatory employee training and a "constant vigilance to make sure our equipment meets all the standards to provide a safe work environment," he said.

Stallbaumer still gets flashbacks about the DeBruce explosion. He said he quit his job after it and went into the aircraft industry. His voice breaks when he remembers his buddies who died, and he said he still thanks God every day that he survived. He's done with elevators.

"I'll never go near one again," he said.


Crumb reported from Des Moines, Iowa. Associated Press writer John Hanna contributed to this report from Topeka, Kan.