Chernobyl (Ukraine): A memorial service was held in Chernobyl on Monday to commemorate the firefighters who died in the aftermath of the 1986 nuclear disaster.
Reactor No. 4 at the power plant 110 kilometres (65 miles) north of Ukraine's capital Kyiv exploded and caught fire deep in the night on April 26, 1986, shattering the building and spewing radioactive material high into the sky.
Firefighters from the local town of Chernobyl were the first on the scene.
Dozens were killed – both in the immediate aftermath, or later from injuries sustained during their work at the destroyed reactor.
Soviet authorities made the catastrophe worse by failing to tell the public what had happened — although the nearby plant workers' town of Pripyat was evacuated the next day, the two million residents of Kyiv weren't informed despite the fallout danger.