Georgian Prime Minister Zurab Zhvania, who helped lead the revolution that toppled the corruption-tainted regime of Eduard Shevardnadze, was killed early Thursday by an apparent natural gas leak, the ex-Soviet republic's interior minister said. Zhvania, 41, was at a friend's apartment when the leak occurred, Interior Minister Vano Merabishvili said in a live broadcast on Rustavi-2 television. "It is an accident," Merabishvili said. "We can say that poisoning by gas took place."