Steel arch to mark Chernobyl site
Construction has started on a gigantic steel arch to cover the remnants of the Chernobyl reactor in Ukraine on the 26th anniversary of the world's worst nuclear accident.
President Viktor Yanukovych is inaugurating the initial assembly of the arch - big enough to house the Statue of Liberty in New York - over the reactor site.
When the arch is completed in 2015, the delicate and dangerous job of dismantling the reactor and cleaning vast amounts of radioactive waste can begin.
The explosion on April 26, 1986, spewed a cloud of radiation over much of the Northern Hemisphere, forcing hundreds of thousands of people from their homes in heavily hit areas of Ukraine, Belarus and western Russia as thousands of square miles were contaminated.