Is it a crime — should bosses go to prison — when bankers wreck government-insured banks and impoverish their own shareholders by making lots of risky loans that don't get paid back?

Or is banking failure, at worst, a question for the civil courts, settled (if at all) by using a slice of a bank's remaining assets to pay partial damages to disappointed investors — who, after all, take a risk when they buy public companies?

One of the few federal criminal cases to arise out of the financial collapse of the late 2000s reached closing arguments in Wilmington on Monday, as Assistant U.S. Attorney Robert Kravetz spent more than four hours summarizing five weeks of testimony in the case against four top executives of the former Wilmington Trust Corp.

That's after District Judge Richard G. Andrews spent most of the morning reading his own detailed instructions to the jury, urging them to vote carefully on each accusation against each executive, as the jurors read along on copies of Andrews' instructions.

Summarizing testimony by federal investigators and some of the bank executives' former underlings, Kravetz accused the bank bosses of fraud, conspiracy, and filing false Securities and Exchange Commission and bank regulatory reports. They lied — and "the lie mattered," as investors and regulators were fooled, losses grew in the darkness and finally overwhelmed the bank, he told the jury.

The government alleges that the bank's leaders hid the bank's dire financial condition, disguising hundreds of millions of dollars in sloppy loans to southern Delaware and shore developers — and insisting, instead, that the bank had few bad loans, and that the losses were declining — even as the recession of 2008-09 was deepening — so they could sell more stock and keep control of what was, at the time, the largest bank still based in the Philadelphia area.

In testimony from Joseph Terranova, one of several former Wilmington Trust bankers who have been found guilty of fraud since regulators pushed the troubled bank into a discount-priced takeover by M&T Bank of Buffalo in 2010, and in exhibits of internal bank correspondence, Kravetz and his fellow prosecutors sought to show that bankers led by then-Wilmington Trust President Robert V.A. Harra Jr. illegally instructed lower-ranking managers to misclassify bad loans so the bank would not have to disclose they were in danger of default.

Terranova testified in a plea bargain that could limit his sentence.

Harra's codefendants are former Wilmington Trust chief financial officer David Gibson, former chief credit officer William North, and former controller Kevyn Rakowski.

The defense, including Wilmington lawyer Michael Kelly and other local and out-of-town counsel, insisted that Harra and his colleagues had engaged in common banking practices: So long as borrowers had made arrangements the bankers believed would eventually result in loan payments, they told the jury, it wasn't strictly necessary for the bank to warn that their loans were late or to classify them as defaulted, even if they had fallen many months behind on their principal payments.

Kelly sought to portray the government's detailed case as confusing and meandering, likening Kravetz to the kind of storyteller who doesn't get to the point. He said the government hadn't proved the bankers "intended" to deceive shareholders or regulators. He noted that some of the lenders cited by the prosecution had themselves been fired by the bank for violating company policy.

And the bank had been holding late loans to developers on the books without declaring them in default for many years, Kelly added, noting Harra and his colleagues acted in apparent good faith, without complaints from regulators — until the Great Recession stalled home buyers and the developers who had planned to build sprawling neighborhoods were left unable to repay their loans.

If regulators didn't complain until it was too late, that's because Wilmington Trust made a practice of hiding bad loans so they never knew about them — flouting regulatory and industry rules as well as its own guidelines, Kravetz said, citing testimony.

Wilmington Trust went easy on big, risky loans to developers and hid the danger from investors and regulators — but didn't cut that kind of slack to mortgage or credit-card borrowers or small businesses, which had to pay what they owed, or else, Kravetz said.

Successor M&T agreed last fall to pay the government and investors $60 million to settle its own alleged criminal liability. But M&T was obliged to continue paying the ex-bankers' legal defense bills.

Some of the bank's former shareholders, who included mutual and pension funds and members of the founding du Pont family, lost hundreds of millions of dollars in shareholder value in the bank's final year. Some have sued in civil court to recover losses. Those suits have been sidelined, awaiting the criminal verdict.

The government has not filed a case against the bank's former chairman and chief executive officer, Ted T. Cecala. Prosecutors would say only that their investigation has not concluded, even as the main case reached trial.

Cecala was represented during the government's investigations by Colm Connolly, a former federal prosecutor who has since been nominated by President Trump for a federal judgeship.