THE NEW YORK TIMES on Saturday, August 14, 2010 reported "a runaway maintenance train on London's Underground system speeding downhill for 13 minutes - four miles - toward the heart of the city as the authorities worked frantically to clear its path of trainloads of unwitting commuters." The train was working on the Northern Line and at 6:44 AM broke loose from its locomotive and rolled backward reaching a speed of about 35 mph "finally halting as it reached the uphill slope at Warren Street station at 6:57 a.m." "Within seconds, engineers relying on an emergency alert system sent out radio appeals, calling on operators to clear the track of around a dozen passenger trains filled with sleepy morning comuters."
See www.nytimes.com/pages/world (http://www.nytimes.com/pages/world) for the complete story.