More homes burn to the ground. Nightly news begins right now. Announcer the Democratic National convention. This is nbc nightly news with lester holt reporting tonight from philadelphia. Good evening. As we come on the air, the roll call vote is under way on the floor below us. And we expect that before we are off the air, Hillary Clinton will be the official nominee of the Democratic Party, the first woman to get the nomination of a major party. Its a moment of political history for certain, but one that Hillary Clinton and her campaign will have little time to bask in as her team aims to mend tears in the party. And to recast her image after republicans last week painted her in the harshest of terms. Bill clinton will take the stage tonight to make the case for his wife. Kristen welker leads us off with the latest. Reporter lester, good evening, an incredible moment happening right now, all 50 delegations casting their votes. We have heard some cheers and also some jeers, emotions ru