Congress grilled regulators on their actions before and after the failures.

Top officials from the Federal Reserve, the Treasury and the Federal Deposit Insurance Corporation on Tuesday defended their response to the collapse of two banks that shocked the global financial system this month and ramped up the risk of a recession in the United States.

The officials blamed the leaders of the two failed banks, Silicon Valley Bank and Signature Bank, saying gross mismanagement had led to the crisis. While members of the Senate Banking Committee also cited executives’ failures, they sharply questioned the regulators about their actions.

Michael S. Barr, the vice chair for supervision at the Fed, SVB’s primary regulator, said the bank failed because “its management failed to appropriately address” clear risks that were pointed out to it more than two years ago. But he later acknowledged that he did not learn about the severity of the bank’s problems until the middle of last month.

Here’s what to know:

• The officials who testified were Mr. Barr; Martin Gruenberg, the chair of the F.D.I.C.; and Nellie Liang, the Treasury’s under secretary for domestic finance. Read more about them.

• Mr. Barr said the run that led to the failure of Silicon Valley Bank was of “an extraordinary pace and scale.” The bank had $42 billion flow out on March 9 — the fastest run ever — and the bank expected an outflow of $100 billion the next day, when regulators stepped in. Catch up on what happened with the banks at the center of the crisis.

• Some Democrats on the committee emphasized the notion that deregulation left agencies without the tools they needed to address issues at smaller banks like SVB. Some Republicans sought to link government spending and the Fed’s broader agenda — including on issues like climate change — to the crisis. Both sides expressed concern about the effect the turmoil could have on the broader economy.

• In response to questions about their actions to backstop deposits at the failed banks, Mr. Gruenberg said that there would have been “contagion” — a spreading of the crisis. Ms. Liang agreed, saying without federal action, bank runs “would have intensified and caused serious problems.” Here are the regulatory proposals that the White House is weighing.

• This was the first of two days of testimony. The same officials will appear before the House Financial Services Committee on Wednesday.