Enron Corp. founder Kenneth Lay declared his innocence Monday on the witness stand, somberly saying the company’s legacy of lost jobs and wrecked retirement savings pained him even more than the loss of a loved one.

Lay blamed the implosion of Enron, once the nation’s seventh-largest company, on a series of devastating circumstances that included theft by the chief financial officer, negative press, a bear market and investor anxiety after the Sept. 11 attacks.