Legasov commits suicide in the first scene of the first episode — and the series makes it clear that he is dying from his long-term exposure to radiation at Chernobyl.

My question about what really happened: do we have proof that he did indeed hang himself or could the KGB have murdered him because they were unhappy about his revelation of the cause of the disaster? Putin’s apparent plans to attribute the catastrophe to some CIA agent has led me to this tin-foil path.