Americans may have to wait longer to find out what really happened to the ill-fated solar-panel maker Solyndra. Tuesday, two top executives at the company said they’ll plead the fifth at a House hearing Friday. The move to decline answering questions comes as the House Oversight committee investigates the company’s failure and $535 million loan from the Department of Energy. Solyndra defended itself, arguing in a statement that it thought investors and the government would back the company financially. “The company is not aware of any wrongdoing by Solyndra officers, directors, or employees in conjunction with the DOE loan guarantee or otherwise,” the company wrote. The investigation will also inspect the wireless startup and Democratic donor LightSquared, and whether the White House pressured a general for the company’s benefit.