WASHINGTON (AP) - U.S. officials say that after a lengthy delay, the military has opened an investigation into a Taliban attack on a base in southern Afghanistan last September that killed two Marines and destroyed six Marine aircraft. Marine Maj. Gen. Charles M. Gurganus was the senior commander in charge at the time. Officials said Thursday that his promotion to three stars has been placed on hold pending the outcome of the investigation. The probe by U.S. Central Command will seek to determine whether anyone in the U.S. military chain of command - including Gurganus - was at fault for failing to prevent or stop an attack that destroyed almost an entire squadron of Marine AV-8B Harrier jets valued at $200 million. Fifteen Taliban fighters breached the base's perimeter without being seen.