now, defense officials deny kherson has fallen. they say a battle is still raging for control of that city. cnn has not been able to verify the russian claims. and shelling in the southern town of mariupol. dozens reported injured there. electricity has been cut off. and at a nuclear power plant, they are blocking entrance. they want to safeguard multiple nuclear sites. a russian delegation will be in place today for a new round of talks. you the other side may not be there. let's go first to nick paton walsh live in odesa, ukraine in the south where many eyes are trained right now. what's going on?