– The corn wasn’t flowing out of the grain bin any longer, so farmer John Daley stepped inside to look more closely.

The corn clumped together and rose higher at the sides, and as Daley stepped onto an outer patch of grain, normally packed enough to be sturdy, his feet crashed through and he tumbled toward the center. Corn raced up like a rockslide to his chest and into his mouth and nose — dusty and dry, the stuff they feed hogs.

It took Winona County firefighters who had been freshly trained in a grain bin rescue course nearly three hours to pull out the 80-year-old Daley. He would have suffocated if he had shared the fate of most farmers engulfed by grain.

Despite widespread technological advances on farms, dozens of people each year become trapped in grain bins — leading to many deaths that experts say are usually preventable.

With harvest season set to begin, some in the agricultural industry worry that farmers are particularly vulnerable as a likely record corn crop of 14 billion bushels pushes vast amounts of grain into storage.

While U.S. grain bin accidents have fallen from a peak of 59 in 2010, they have crept up again in recent years.

In June, the number of people entrapped in grain bins nationwide already had surpassed last year’s total of 33, said Bill Field, a Purdue University researcher who tracks such incidents.

“Nationwide, this trend … should be on the decline, but it’s not,” he said.

Rescuers pulled a Breckenridge, Minn., man from a grain bin last week, while a second farmer in northern Iowa survived a similar accident. In June, a 9-year-old boy in southeast Wisconsin died after climbing into a grain bin on his family’s farm. A man in Granite Falls, Minn., three men in North Dakota and a man in Iowa also died in the last 14 months. Two other men in rural Minnesota were rescued in separate incidents this year.

Precise numbers are hard to come by because the Occupational Safety and Health Administration doesn’t have jurisdiction over the small family farms where grain bin accidents commonly take place. And many of the accidents are never reported if they are not fatal, researchers say, rendering Purdue’s numbers smaller than the true figure.

The Upper Midwest, where corn remains king, has accounted for nearly a third — 337 — of grain bin entrapments since Purdue began tracking the problem in 1964. Minnesota, the Dakotas, Iowa and Wisconsin saw at least five reported accidents in 2013, while the Star Tribune counted at least 12 so far this year based on news reports.

“You’re moving more grain, there’s more chances for accidents,” said Dale Ekdahl, who sells rescue equipment and runs a grain bin rescue center in northwestern Minnesota. He started the enterprise four years ago, after a 9-year-old in Herman, Minn., died in a grain bin.

“Believe me, it’s a really, really dangerous business nowadays.”

Grain already piled up

Grain bin entrapments can happen when farmers step into a grain bin alone — particularly if they’ve left the auger running.

“It only takes a minute at the rate that grain flows,” said Field. “They’re buried beyond where they can escape on their own, and often they’re working alone, so there’s no one there to shut the system off.”

As farmers produce bigger crops, grain bins have also multiplied and become larger.

More recently, trains busy carrying crude oil from North Dakota’s Bakken region have delayed grain shipments across the Upper Midwest. That’s left more grain sitting in bins and elevators even before the harvest begins.

Meanwhile, the higher moisture content in last year’s crop — expected to continue this year — heightens the risk of corn molding and crusting together, a threat that draws in farmers who then step on the equivalent of a false bottom as they step inside to break up the grain.

That’s what happened at Daley’s farm. Inside the bin, the grain pushed up against his body so hard, he recalled, that “it felt like a sumo wrestler comin’ up behind you, putting his arms over his chest and just — you know, arrrgh — squeezing.”

By the time a victim is submerged, there is little hope.

In February, Clarkfield Fire Chief Francis Staab rushed down a distant gravel road after receiving a call that a local farmer had gone missing. He and rescue workers gathered around a grain bin and saw that the grain was flowing “like you fill a cup with the sand and somebody cut a hole in the bottom of it,” he recalled.

They shut the auger off and looked for a glimpse of a hat or glove from the farmer, 77-year-old David Rosetter. Finally, the men cut the bin open, trying to unleash the grain while maintaining the structure’s balance. They toiled for nearly eight hours in the winter chill before they found Rosetter dead at the bottom.

Practicing for disaster

Two firefighters from Dumont, Minn., sank into the middle of the bin, corn rushing toward their waists as the auger whirred.

“I know I’m not getting out now,” quipped Steve Grimes, as the kernels slowed.

He and the other entrapped man, Dean Frisch, could hardly feel their legs, and the force of the grain was enormous.

They were at Ekdahl’s training center in Elbow Lake, preparing for the possibility that they would one day field a call to save someone trapped in a grain bin.

The Dumont fire department is part of a renewed push to train first responders in grain bin rescues. Dozens of rural fire departments across the Midwest have been taking such training as technology and awareness of the problem has improved.

“As some of these farm bins get bigger and bigger all the time, there’s really a need for additional farmer education about proper bin entry and procedures,” said Bob Zelenka, executive director of the Minnesota Grain and Feed Association.

The Wheaton Dumont Co-op Elevator paid for grain rescue technology in 11 of the communities where it operates, spanning the Dakotas and western Minnesota, and directed the firefighters to go to Elbow Lake to test it out.

The firefighters charged with saving Grimes and Frisch had already found their rhythm. They sprang forward to form a circular blockade around the men by sliding together curved aluminum panels, called rescue tubes.

“You want to keep it as round as possible,” Ekdahl called out, urging them to add another panel.

The rescuers jumped on rungs attached to the outside of the panels to knock them down as far as the men’s knees, still buried deep. Then they handed Grimes and Frisch pails to start shoveling corn from inside to outside the panels so they could climb out.

The rescue took just eight minutes, though a real one could stretch for hours.

Grimes has regularly stepped into grain bins on his farm, but the feeling of being sucked into quicksand that evening made him wonder if he should be more careful. “The more you squirm and the more you try to get out, the deeper you go,” he said. “It makes you think a lot.”

Rescue in Lewiston

In Lewiston, Daley awoke one morning in June to help the farmers who leased out his grain bins. Stooped with age but still energetic, he hurried past the sprawling maple tree to his bins, which flanked long rows of corn to the east and west across County Road 25.

One of the other farmers, Greg Smith, said it must be out of corn, since none was flowing. Daley figured that couldn’t be right. He climbed 34 rungs up the ladder, then down inside the steel cylinder to see for himself.

Even after he tumbled down, a second avalanche of corn struck him from behind and he stopped breathing for a few moments as it sailed over his head.

Daley knew he wasn’t supposed to just step on the grain, but, “the bottom line is, you make one mistake and you cancel out 50 years of doing it right,” he said.

Firefighter Mike Plass, who had once worked for Daley as a farmhand, and other emergency workers found Daley with only his arms free. He had grain up to his neck and was scooping it away from his mouth.

They erected panels around his body to keep the grain out — different than the ones Ekdahl sold — but Daley was still locked in. An onlooker suggested bringing over a tool from the feed store that would vacuum up the grain. They attached it to a neighbor’s tractor.

In the end, they filled two semitrailer trucks with the grain they sucked loose “and it seems like we didn’t hardly touch the grain in there,” said Plass. “It’s unbelievable how much grain is coming in, and people don’t realize how fast. This is the scary part.”