a special homecoming for march madness' cinderella squad. and a violinist's impromptu concerts in a bomb shelter, inspiring ukrainians in their darkest hours. good evening, everyone. thanks so much for joining us on this sunday. i'm linsey davis. we begin tonight with the relentless russian bombardment of ukraine. there are reports that an art school in the beseiged city of mariupol was destroyed by russian forces, with as many as 400 sheltering inside. and russian commanders with an ultimatum, ordering ukrainian forces in the city to surrender within hours. that city is increasingly feeling the brunt of putin's war, undergoing a fierce assault. many residents spent today digging graves for their neighbors. putin's ground forces making little progress in their advance toward kyiv, leading some military analysts to predict a long and bloody stalemate ahead.