As he stood before a crowd of cheering fans in a Maryland gym, Tim Krieger knew his glory days as one of America's top amateur wrestlers were nearing the end.

It was 1987, and Krieger had just completed an undefeated season and won the first of his two national titles. With sweat dripping off his Iowa State wrestling singlet, he wondered if anything could top this.

"When I won, I thought, 'What is it going to be like when I can't feel like this anymore?' " Krieger later told reporters.

Krieger delayed that painful moment for more than two decades, as he found new foes to conquer in the high-stakes world of commodities trading. In some years he made as much money as top executives at Minnesota's biggest companies by wagering in the arcane world of electricity futures.

But he could not stay on top forever. Krieger's latest Minneapolis-based company, Aspirity Energy, filed for bankruptcy on June 30. In court, he said he faces "financial ruin."

Now Krieger is in the middle of a legal fight over what went wrong. Former employees are angry that he received at least $18 million from his failing business before firing his workers and closing the doors. Todd McRae, a former risk analyst for Krieger's company, has complained to the U.S. Securities and Exchange Commission, alleging that his former boss committed fraud when he shifted millions of dollars in assets out of the business, leaving it incapable of meeting its obligations.

In an interview, McRae said he believes Aspirity was "set up to fail."

Krieger declined multiple ­interview requests though his attorney, Janel Dressen. Though Krieger initially agreed to respond to written questions, he later declined after the Star Tribune provided a three-page summary of its reporting.

Dressen said Krieger would not provide any statement considering "the numerous inaccuracies in the information you have received, the misrepresentations and incomplete information as presented in your many questions."

SEC officials declined to comment on whether Krieger is the subject of an investigation. More than 700 investors stand to lose about $30 million in unsecured loans that were used to fund his operations.

"You have to ask yourself, Did he [Krieger] structure this in a way in which he intended to strip out all of the cash and leave all of these debt holders high and dry?" asked Dale Johnson, former chief financial officer of Twin Cities Power, Krieger's main operating company. "And if so, there has to be some rule out there he broke that says he can't do that."

Determination to win

Krieger's success in commodities, according to longtime associates, had a lot do with the traits that made him a four-time All-America wrestler.

Jerry Ray, Krieger's high school wrestling coach, said Krieger lacked "natural ability" but won three state titles because he was disciplined, confident and worked harder than any other wrestler on the team, showing up at school many mornings to work out by himself before classes began.

"He grew up as a nasty kid on the mat," Ray said. "People didn't want to mess with him."

Krieger's first big break in business came in 1995, when he went to a wrestling match and bumped into Larry Zilverberg, the owner of a trading business in Minnetonka, court records show.

Zilverberg, a three-time Big Ten wrestling champ, invited Krieger to quit his job as a stockbroker and start trading cheese and other dairy products for his company, North Central.

"I originally sought people out who had previously been athletes," Zilverberg said in a court proceeding, explaining that successful traders need to be fiercely competitive.

Krieger became a star on the dairy desk, matching manufacturers stuck with trucks full of "off-grade" cheese with buyers who could use a product with too much moisture or another defect. One of the firm's regular customers: a mink ranch in northern Wisconsin that fed this cheese to the animals.

Krieger flourished. Within four years, court records show, his annual earnings climbed from $20,000 to $125,000.

Rising ambitions

Despite his success, Krieger wasn't satisfied. He joked that anybody could do the job, describing himself and two colleagues as "three monkeys on the phone" in a court ­proceeding.

In 1999, anxious for new challenges, Krieger quit North Central to start his own trading business. Two co-workers went with him, including John Beatty, also a winner of two national wrestling titles.

The new company thrived, but Krieger continued to seek bigger opportunities. In 2004, after meeting a trader who dealt in electricity futures, Krieger decided he had found the right place to invest his $1 million in savings, records show.

At the time, electricity was a relatively new market. Compared to cheese, it was also extraordinarily difficult to master. Traders use complex algorithms to help them figure out where prices are heading.

Krieger saw big dollar signs, even though he barely understood the business, according to associates. Krieger has acknowledged his shortcomings, admitting to regulators in 2012 that his knowledge of power trading is "infinitesimally small."

"I've never traded a megawatt, so I've got to put the right people in the right place to manage the business," he said in the deposition.

Krieger's main role was to raise the capital needed to finance his traders' deals. In 2006, he hooked up with Bob Schachter, one of Minnesota's most successful grain traders, who agreed to help bankroll Twin Cities Power, Krieger's new energy company.

Business was good. In the first three years, according to former employees, the company hired some of the nation's top energy traders by offering unusually attractive compensation packages. New offices sprouted in New Jersey, Oklahoma, even Canada. In its first three years, Twin Cities Power generated a total of $76 million in gross profits on energy trading, court records show.

Things turned sour, however, when Krieger and other owners took cash distributions of $10 million in 2009, a year in which the company made some bad trades and lost $1.7 million on revenue of $16.6 million.

"Krieger wasn't taking a ­salary, so we said it was acceptable for them to take some money out," Schachter said in an interview. "But we didn't realize how much and how often they were doing it. … And he [Krieger] showed no inclination to put money back in. So I saw no reason to take all of this risk."

In 2010, Schachter and his partners decided to call in their loans, triggering a legal battle that almost sank the company.

New investors

Though the dispute was ultimately settled through arbitration, Krieger had to repay more than $30 million that Schachter and his partners had invested in the business. The loss of the company's chief backer caused problems from which Twin Cities Power never fully recovered.

To repay Schachter, Krieger shut down his trading operation in Canada. The move freed up $15 million to $20 million in capital, but it also eliminated an aggressive trading group that had been producing the most profits, records show.

To finance the business, Krieger turned to the internet. In 2012, Twin Cities Power began marketing up to $50 million in unsecured subordinated notes, a small-scale form of junk bonds. The buyers were investors looking for high yields, typically about 14 percent.

The risks were high, and investors were told they could lose everything. But employees said Krieger remained upbeat, even when the company started to hemorrhage money.

In 2015, with profits tanking, Krieger changed the name of the company to Aspirity and transferred most of its remaining assets — including its core trading business — to his private company, now known as Diversified Trading. Aspirity received a $22 million term loan.

In a letter to investors, he said the move offered "tremendous opportunities for stable and profitable growth without the risks inherent in the power trading business."

But the new company's only business, besides collecting interest on the loan to Diversified, was selling retail electricity to homeowners in deregulated states. And that business had never been profitable for Aspirity, records show. All of the company's operating income came from trading.

The moves were disastrous for Aspirity, but not for Krieger. In 2015, Aspirity lost $4.7 million but Krieger personally earned more than $5 million, the vast majority of that through distributions of the firm's dwindling cash reserves, records show. In 2016, Aspirity lost $12.9 million on revenue of $13.5 million, and its auditors issued a "going concern" warning.

Reorganization efforts

Former employees said the company might have been able to recover if Krieger had put more of his profits back into the business when things were good. Instead, records show that he has reinvested $500,000 since 2011 while taking more than $18 million in salary and distributions.

Now he says the money is gone. In a July affidavit, he said he has been reduced to selling personal assets to pay his bills, and he said it's "unlikely" he will be able to continue making loan payments to Aspirity.

"I am facing financial ruin, laying off employees, shutting down my business and may be facing hundreds of lawsuits for the bankruptcy of Aspirity and the possible bankruptcy of Diversified Trading," Krieger said in the affidavit. "The SEC will be involved. This is what keeps me up at night."

Krieger won't go down easily, however. His wife, Whitney, whom he sued for divorce this year, said in filings that Krieger recently texted her that he plans to "start up again without the big debt and overhead" and that his new job would pay him $500,000 to $1 million per year.

Aspirity President Scott Lutz, who hopes to reorganize the company, also says not to underestimate the resilient Krieger, who remains the company's chairman and majority owner. "He wasn't 116-3 at Iowa State for nothing."