WASHINGTON - The White House on Tuesday described the death of al-Qaida deputy leader Abu Yahya al-Libi as a "major blow" to the militant group and said there was no clear successor to take over his role.White House spokesman Jay Carney, citing US intelligence sources, said Libi was al-Qaida's "general manager" responsible for overseeing day-to-day operations in the tribal areas of Pakistan, and managing relations with affiliates."We have confirmation of his death," Carney told a news briefing, declining to say where or how the network's deputy leader died. "There is now no clear successor to take on the breadth of his responsibilities," he said.