Workers in the 55-storey Torre Mayor (main tower), which stands at 225 meters (837 feet) tall, take part in an evacuation exercise in a simulated disaster in Mexico City, September 18, 2009. The exercise is part of the authorities' efforts to promote action in a disaster as part of a memorial service to victims of the September 19, 1985 Mexico City earthquake. The 1985 earthquake measured 8.1 on the Richter scale and caught Mexico off guard, killing thousands as it toppled housing blocks and office buildings in a city built on the soft mud left by a dried-up pre-Hispanic lake. Some 12,000 people are believed to have died in that earthquake, with another 40,000 injured. REUTERS/Jorge Dan Lopez (MEXICO DISASTER SOCIETY)
REUTERS/STRINGER/MEXICO