The Department of Homeland Security on Friday lowered its terrorism alert level for buses, subways and trains effective on Friday night — a month after raising it in response to bombings in London. “These changes will be effective at 8:00 p.m. local time on Friday, August 12, following local rush hours across the country, at the discretion of state and local authorities,” Homeland Security Secretary Michael Chertoff said in a statement. The department had raised the alert level to a “high” risk of attack from “elevated” on July 7, after bombings on the London transport system killed more than 50 people.Full Story