WASHINGTON  Summoned to Capitol Hill to explain their companies’ roles in the worst economic downturn since the Depression, leaders of four big Wall Street banks offered a largely clinical take on the financial crisis on Wednesday, pointing to lapses in risk management and government regulation but offering little sense of the turmoil’s human toll.

Testifying to the Financial Crisis Inquiry Commission, the body established by Congress to determine the causes of the Wall Street debacle, Lloyd C. Blankfein, the chairman and chief executive of Goldman Sachs, drew most of the fire.

Mr. Blankfein parried repeated questions over his bank’s extraordinary profits and salaries. At one point, when he likened aspects of the financial crisis to a “hurricane” and similar acts of God, the commission’s chairman, Phil Angelides, a Democrat and former California state treasurer, cut in to say, “Acts of God, we’ll exempt. These were acts of men and women.”

Mr. Angelides and the other commission members challenged the bankers on executive pay and reckless underwriting and trading, often in withering terms.