The Government Knew The Danger Of The Explosion
In the days immediately following the explosion, the government dispatched a fleet of planes and helicopters to drop over two tons of boron, lead, and other substances that would absorb some of the radiation onto the power plant. They also dispatched soldiers who shovel graphite off of the reactor.
For over a week, Chernobyl was absolutely awash with government activity. The government knew that there was a genuine danger to the people of Chernobyl, but officials did not take any precautions to protect them. By the time the evacuation began, many people would have received a lethal dose of radiation.