After the explosion a large amount of radioactive material from Reactor No 4 was thrown onto the roof of Reactor No 3, which was still operating (the other reactors were generating for several years after the accident). Other countries offered robots to go onto the roof to scoop up the radioactive material and basically chuck it into Reactor No 4's hole. But the extent of the radioactivity had been under-stated and the robots failed to operate. In the end, they sent in people - liquidators - who suited up in basic lead-line clothing and had just 2 minutes to get on the roof and hand shovel as much material as they could back into the radioactive mess and get out again. Unbelievably brave.
Meanwhile, in Pripyat, a town built in 1970 and designed to accommodate the power plant workers and their families, an evacuation took place two days after the accident. A population of nearly 50,000 people had one hour to pack essentials - passports and money basically - and leave on coaches. They were told they would only be moving away for a few days. They never returned. Thirty one years later Pripyat is a ghost town and nature has already started to reclaim the city.