Chernobyl Timeline By timelinemakingmaster Apr 25, 1986 Reactor 4 shut down Apr 26, 1986 Explosive destruction of reactor 4 at 1:23 am Apr 26, 1986 First fire put out by 5 am Apr 27, 1986 Evacuations commence and 30km exclusion zone established Apr 29, 1986 Nuclear fallout covered Ukraine and Belarus, reaching as far as Scandinavia May 15, 1986 116,000 people evacuated