From Time: The FBI has long been worried about the vulnerability of the nation’s rail system to terror attack. But the threat was deemed immediate enough late last week for the agency to issue a formal warning. The alert cautioned that al-Qaeda, “possibly using operatives who have a Western appearance,” might try to destroy key rail bridges, derail trains or target hazardous-material containers. What prompted the unusually specific warning? Intelligence sources tell Time it came as a result of the attack by two gunmen who killed one U.S. Marine and wounded another on a Kuwaiti island on Oct. 8. Kuwaiti authorities who afterward raided an al-Qaeda cell believed to be supporting the gunmen found a computer hard drive with photos of American passenger and cargo trains as well as rail crossings. At about the same time, senior al-Qaeda operatives in custody told their CIA and FBI interrogators that the organization had plans for targeting railroads.